Hereditary information is information about the structure of a protein (information about which amino acids in what order combine during the synthesis of the primary structure of the protein).

Information about the structure of proteins is encoded in DNA, which in eukaryotes is part of the chromosomes and is located in the nucleus. The section of DNA (chromosome) that encodes information about one protein is called gene.

Transcription- this is the rewriting of information from DNA to mRNA (messenger RNA). mRNA carries information from the nucleus to the cytoplasm, to the site of protein synthesis (to the ribosome).

Broadcast is the process of protein biosynthesis. Inside the ribosome, tRNA anticodons are attached to mRNA codons according to the principle of complementarity. The ribosome links the amino acids brought by the tRNA with a peptide bond to form a protein.

The reactions of transcription, translation, and replication (doubling of DNA) are reactions matrix synthesis. DNA serves as a template for mRNA synthesis, mRNA serves as a template for protein synthesis.

Genetic code is the way in which information about the structure of a protein is recorded in DNA.

Genecode Properties

1) Tripletity: one amino acid is encoded by three nucleotides. These 3 nucleotides in DNA are called a triplet, in mRNA - a codon, in tRNA - an anticodon (but in the exam there may be a “code triplet”, etc.)

2) Redundancy(degeneracy): there are only 20 amino acids, and there are 61 triplets encoding amino acids, so each amino acid is encoded by several triplets.

3) Unambiguity: each triplet (codon) codes for only one amino acid.

4) Versatility: the genetic code is the same for all living organisms on Earth.

Tasks

Tasks for the number of nucleotides / amino acids
3 nucleotides = 1 triplet = 1 amino acid = 1 tRNA

Tasks at ATHC
DNA mRNA tRNA
A U A
T A U
G C G
C G C

Choose one, the most correct option. mRNA is a copy
1) one gene or group of genes
2) chains of a protein molecule
3) one protein molecule
4) parts of the plasma membrane

Answer

Choose one, the most correct option. The primary structure of a protein molecule, given by the mRNA nucleotide sequence, is formed in the process
1) broadcasts
2) transcriptions
3) reduplication
4) denaturation

Answer

Choose one, the most correct option. Which sequence correctly reflects the way of realization of genetic information
1) gene --> mRNA --> protein --> trait
2) trait --> protein --> mRNA --> gene --> DNA
3) mRNA --> gene --> protein --> trait
4) gene --> DNA --> trait --> protein

Answer

Choose one, the most correct option. Choose the correct sequence of information transfer in the process of protein synthesis in the cell
1) DNA -> messenger RNA -> protein
2) DNA -> transfer RNA -> protein
3) ribosomal RNA -> transfer RNA -> protein
4) ribosomal RNA -> DNA -> transfer RNA -> protein

Answer

Choose one, the most correct option. The same amino acid corresponds to a UCA anticodon on transfer RNA and a triplet in a gene on DNA
1) GTA
2) ACA
3) TGT
4) TCA

Answer

Choose one, the most correct option. The synthesis of hemoglobin in the cell controls a certain segment of the DNA molecule, which is called
1) codon
2) triplet
3) genetic code
4) genome

Answer

Choose one, the most correct option. The same amino acid corresponds to the CAA anticodon on transfer RNA and the triplet on DNA
1) CAA
2) TSUU
3) GTT
4) GAA

Answer

Choose one, the most correct option. AAU anticodon on transfer RNA corresponds to a triplet on DNA
1) TTA
2) AAT
3) AAA
4) TTT

Answer

Choose one, the most correct option. Each amino acid in a cell is encoded
1) one DNA molecule
2) several triplets
3) multiple genes
4) one nucleotide

Answer

Choose one, the most correct option. Functional unit of the genetic code
1) nucleotide
2) triplet
3) amino acid
4) tRNA

Answer

Choose one, the most correct option. Which transfer RNA anticodon corresponds to the TGA triplet in the DNA molecule
1) ACU
2) ZUG
3) UGA
4) AHA

Answer

Choose one, the most correct option. The genetic code is universal because
1) each amino acid is encoded by a triplet of nucleotides
2) the place of an amino acid in a protein molecule is determined by different triplets
3) it is the same for all creatures living on Earth
4) several triplets code for one amino acid

Answer

Choose one, the most correct option. The section of DNA containing information about one polypeptide chain is called
1) chromosome
2) triplet
3) genome
4) code

Answer

Choose one, the most correct option. Translation is the process by which
1) the number of DNA strands doubles
2) mRNA is synthesized on the DNA template
3) proteins are synthesized on the mRNA template in the ribosome
4) hydrogen bonds between DNA molecules are broken

Answer

Choose one, the most correct option. The translation matrix is the molecule
1) tRNA
2) DNA
3) rRNA
4) mRNA

Answer

TRANSCRIPTION - BROADCASTING
1. Establish a correspondence between the processes and stages of protein synthesis: 1) transcription, 2) translation. Write the numbers 1 and 2 in the correct order.
A) t-RNA amino acid transfer
B) DNA is involved
C) i-RNA synthesis
D) formation of a polypeptide chain
D) occurs on the ribosome

Answer

2. Establish a correspondence between characteristics and processes: 1) transcription, 2) translation. Write down the numbers 1 and 2 in the order corresponding to the letters.
A) three types of RNA are synthesized
B) occurs with the help of ribosomes
C) a peptide bond is formed between the monomers
D) in eukaryotes occurs in the nucleus
D) DNA is used as a template
E) carried out by the enzyme RNA polymerase

Answer

TRANSCRIPTION - TRANSLATION - REPLICATION
Establish a correspondence between characteristics and types matrix reactions: 1) replication, 2) transcription, 3) translation. Write down the numbers 1-3 in the order corresponding to the letters.
A) Reactions take place on ribosomes.
B) The template is RNA.
C) A biopolymer containing nucleotides with thymine is formed.
D) The synthesized polymer contains deoxyribose.
D) A polypeptide is synthesized.
E) RNA molecules are synthesized.

Answer

STREAMING EXCEPT
All but two of the following concepts are used to describe translation. Identify two signs that “fall out” from the general list, and write down the numbers under which they are indicated.
1) matrix synthesis
2) mitotic spindle
3) polysome
4) peptide bond
5) higher fatty acids

Answer

BIOSYNTHESIS
Choose three options. Protein biosynthesis, unlike photosynthesis, occurs
1) in chloroplasts
2) in mitochondria
3) in plastic exchange reactions
4) in reactions of the matrix type
5) in lysosomes
6) in leukoplasts

Answer

BIOSYNTHESIS SEQUENCE
1. Determine the sequence of processes that provide protein biosynthesis. Write down the corresponding sequence of numbers.
1) the formation of peptide bonds between amino acids
2) attachment of the tRNA anticodon to the complementary mRNA codon
3) synthesis of mRNA molecules on DNA
4) movement of mRNA in the cytoplasm and its location on the ribosome
5) delivery of amino acids to the ribosome using tRNA

Answer

2. Establish the sequence of protein biosynthesis processes in the cell. Write down the corresponding sequence of numbers.
1) the formation of a peptide bond between amino acids
2) interaction of mRNA codon and tRNA anticodon
3) release of tRNA from the ribosome
4) connection of mRNA with a ribosome
5) release of mRNA from the nucleus into the cytoplasm
6) mRNA synthesis

Answer

3. Set the sequence of processes in protein biosynthesis. Write down the corresponding sequence of numbers.
1) mRNA synthesis on DNA
2) amino acid delivery to the ribosome
3) formation of a peptide bond between amino acids
4) attachment of an amino acid to tRNA
5) mRNA connection with two ribosome subunits

Answer

4. Set the sequence of steps in protein biosynthesis. Write down the corresponding sequence of numbers.
1) separation of a protein molecule from a ribosome
2) attachment of tRNA to the start codon
3) transcription
4) elongation of the polypeptide chain
5) release of mRNA from the nucleus into the cytoplasm

Answer

5. Set the correct sequence of protein biosynthesis processes. Write down the corresponding sequence of numbers.
1) attachment of an amino acid to a peptide
2) mRNA synthesis on DNA
3) codon recognition of anticodon
4) association of mRNA with a ribosome
5) release of mRNA into the cytoplasm

Answer

BIOSYNTHESIS EXCEPT
1. All the signs below, except for two, can be used to describe the process of protein biosynthesis in a cell. Identify two features that “fall out” of the general list, and write down in response the numbers under which they are indicated.
1) The process occurs in the presence of enzymes.
2) The central role in the process belongs to RNA molecules.
3) The process is followed ATP synthesis.
4) Amino acids serve as monomers for the formation of molecules.
5) The assembly of protein molecules is carried out in lysosomes.

Answer

2. All the signs listed below, except for two, are used to describe the processes necessary for the synthesis of a polypeptide chain. Identify two signs that “fall out” from the general list, and write down the numbers under which they are indicated.
1) transcription of messenger RNA in the nucleus
2) transport of amino acids from the cytoplasm to the ribosome
3) DNA replication
4) the formation of pyruvic acid
5) connection of amino acids

Answer

MATRIX
Choose three options. As a result of reactions of the matrix type, molecules are synthesized
1) polysaccharides
2) DNA
3) monosaccharides
4) mRNA
5) lipids
6) squirrel

Answer

In which of the following cell organelles do matrix synthesis reactions take place? Identify three true statements from the general list, and write down the numbers under which they are indicated.
1) centrioles
2) lysosomes
3) Golgi apparatus
4) ribosomes
5) mitochondria
6) chloroplasts

Answer

Choose from the reactions listed below two related to the reactions of matrix synthesis. Write down the numbers under which they are indicated.
1) cellulose synthesis
2) ATP synthesis
3) protein biosynthesis
4) glucose oxidation
5) DNA replication

Answer

Choose three correct answers from six and write down the numbers under which they are indicated in the table. Matrix reactions in the cell include
1) DNA replication
2) photolysis of water
3) RNA synthesis
4) chemosynthesis
5) protein biosynthesis
6) ATP synthesis

Answer

GENETIC CODE
1. Choose three correct answers from six and write down the numbers under which they are indicated. What are the consequences of replacing one nucleotide with another in the mRNA sequence that codes for a protein?
1) In a protein, one amino acid must be replaced by another.
2) There will be a replacement of several amino acids.
3) Substitution of one amino acid for another may occur.
4) Protein synthesis may be interrupted at this point.
5) The amino acid sequence of a protein may remain the same.
6) Protein synthesis is always interrupted at this point.

Answer

2. Choose three correct answers from six and write down the numbers under which they are indicated. Specify the properties of the genetic code.
1) The code is universal only for eukaryotic cells.
2) The code is universal for eukaryotic cells, bacteria and viruses.
3) One triplet encodes the sequence of amino acids in a protein molecule.
4) The code is degenerate, since one amino acid can be encoded by several codons.
5) 20 amino acids are encoded by 61 codons.
6) The code is interrupted because there are gaps between codons.

Answer

AMINO ACIDS - CODONS mRNA
How many mRNA codons encode information about 20 amino acids? Write down only the appropriate number in your answer.

Answer

AMINO ACIDS - NUCLEOTIDES mRNA
1. The polypeptide region consists of 28 amino acid residues. Determine the number of nucleotides in the mRNA region containing information about the primary structure of the protein.

Answer

2. How many nucleotides does mRNA contain if the protein synthesized from it consists of 180 amino acid residues? Write down only the appropriate number in your answer.

Answer

3. How many nucleotides does mRNA contain if the protein synthesized from it consists of 250 amino acid residues? Write down only the appropriate number in your answer.

Answer

4. Protein consists of 220 amino acid units (residues). Set the number of nucleotides in the region of the mRNA molecule encoding this protein. Write down only the appropriate number in your answer.

Answer

AMINO ACIDS - DNA NUCLEOTIDES
1. Protein consists of 140 amino acid residues. How many nucleotides are in the region of the gene in which the primary structure of this protein is encoded?

Answer

2. Protein consists of 180 amino acid residues. How many nucleotides are in the gene that encodes the sequence of amino acids in this protein. Write down only the appropriate number in your answer.

Answer

3. A fragment of a DNA molecule encodes 36 amino acids. How many nucleotides does this DNA fragment contain? Write down the corresponding number in your answer.

Answer

4. The polypeptide consists of 20 amino acid units. Determine the number of nucleotides in the gene region encoding these amino acids in the polypeptide. Write your answer as a number.

Answer

5. How many nucleotides in the gene region encode a protein fragment of 25 amino acid residues? Write down the correct number for your answer.

Answer

6. How many nucleotides in a fragment of the DNA template chain encode 55 amino acids in a polypeptide fragment? Write down only the appropriate number in your answer.

Answer

AMINO ACIDS - tRNA
1. How many tRNAs took part in protein synthesis, which includes 130 amino acids? Write the correct number in your answer.

Answer

2. A fragment of a protein molecule consists of 25 amino acids. How many tRNA molecules were involved in its creation? Write down only the appropriate number in your answer.

Answer

3. How many transport RNA molecules were involved in translation if the gene section contains 300 nucleotide residues? Write down only the appropriate number in your answer.

Answer

4. Protein consists of 220 amino acid units (residues). Set the number of tRNA molecules needed to carry amino acids to the site of protein synthesis. Write down only the appropriate number in your answer.

Answer

AMINO ACIDS - TRIPLETS
1. How many triplets does a fragment of a DNA molecule contain, encoding 36 amino acids? Write down the corresponding number in your answer.

Answer

2. How many triplets encode 32 amino acids? Write down the correct number for your answer.

Answer

3. How many triplets are involved in the synthesis of a protein consisting of 510 amino acids? In your answer, write down only the number of triplets.

Answer

NUCLEOTIDES - AMINO ACIDS
1. What is the number of amino acids encoded in the gene section containing 129 nucleotide residues?

Answer

2. How many amino acids does 900 nucleotides encode? Write down the correct number for your answer.

Answer

3. What is the number of amino acids in a protein if its coding gene consists of 600 nucleotides? Write down the correct number for your answer.

Answer

4. How many amino acids does 1203 nucleotides encode? In response, write down only the number of amino acids.

Answer

5. How many amino acids are needed for the synthesis of a polypeptide if the mRNA encoding it contains 108 nucleotides? Write down only the appropriate number in your answer.

Answer

mRNA NUCLEOTIDES - DNA NUCLEOTIDES
An mRNA molecule takes part in protein synthesis, the fragment of which contains 33 nucleotide residues. Determine the number of nucleotide residues in the region of the DNA template chain.

Answer

NUCLEOTIDES - tRNA
How many transport RNA molecules were involved in translation if the gene section contains 930 nucleotide residues?

Answer

TRIPLETS - NUCLEOTIDES mRNA
How many nucleotides are in a fragment of an mRNA molecule if the fragment of the DNA coding chain contains 130 triplets? Write down only the appropriate number in your answer.

Answer

tRNA - AMINO ACIDS
Determine the number of amino acids in a protein if 150 tRNA molecules were involved in the translation process. Write down only the appropriate number in your answer.

Answer

JUST
How many nucleotides make up one mRNA stop codon?

Answer

How many nucleotides make up a tRNA anticodon?

Answer

DIFFICULT
The protein has a relative molecular weight of 6000. Determine the number of amino acids in a protein molecule if the relative molecular weight of one amino acid residue is 120. In your answer, write down only the corresponding number.

Answer

There are 3,000 nucleotides in two strands of a DNA molecule. Information about the protein structure is encoded on one of the chains. Count how many amino acids are encoded on one strand of DNA. In response, write down only the number corresponding to the number of amino acids.

Answer

KIT AMK-THREE-NUK
1. In the process of translation of the molecule of the hormone oxytocin, 9 tRNA molecules participated. Determine the number of amino acids that make up the synthesized protein, as well as the number of triplets and nucleotides that this protein encodes. Write down the numbers in the order indicated in the task, without separators (spaces, commas, etc.). 4. Protein consists of 240 amino acids. Set the number of mRNA nucleotides and the number of DNA nucleotides encoding these amino acids, as well as total number tRNA molecules that are needed to carry these amino acids to the site of protein synthesis. Write down three numbers in the order indicated in the task, without separators (spaces, commas, etc.).

Answer

Consider the picture depicting the processes occurring in the cell, and indicate A) the name of the process, indicated by the letter A, B) the name of the process, indicated by the letter B, C) the name of the type chemical reactions. For each letter, select the appropriate term from the list provided.
1) replication
2) transcription
3) broadcast
4) denaturation
5) exothermic reactions
6) substitution reactions
7) matrix synthesis reactions
8) cleavage reactions

Answer

Look at the picture and write (A) the name of process 1, (B) the name of process 2, (c) the end product of process 2. For each letter, select the appropriate term or concept from the list provided.
1) tRNA
2) polypeptide
3) ribosome
4) replication
5) broadcast
6) conjugation
7) ATP
8) transcription

Answer

All of the features listed below, except for two, are used to describe the process depicted in the figure. Identify two signs that “fall out” from the general list, and write down the numbers under which they are indicated.
1) according to the principle of complementarity, the nucleotide sequence of a DNA molecule is translated into a nucleotide sequence of molecules various kinds RNA
2) the process of translating a nucleotide sequence into an amino acid sequence
3) the process of transferring genetic information from the nucleus to the site of protein synthesis
4) the process takes place in ribosomes
5) the result of the process - RNA synthesis

Answer

The molecular weight of the polypeptide is 30,000 USD. Determine the length of the gene encoding it if the molecular weight of one amino acid is on average 100, and the distance between nucleotides in DNA is 0.34 nm. Write down only the appropriate number in your answer.

Answer

Establish a correspondence between the functions and structures involved in protein biosynthesis: 1) gene, 2) ribosome, 3) tRNA. Write down the numbers 1-3 in the order corresponding to the letters.
A) transports amino acids
B) encodes hereditary information
B) participates in the process of transcription
D) form polysomes
D) the site of protein synthesis

Answer

It is known that all types of RNA are synthesized on a DNA template. Fragment
a DNA molecule on which a portion of the central loop of tRNA is synthesized,
has the following nucleotide sequence: HCTTCCACCTGTTCACA.
Determine the nucleotide sequence of the tRNA region that
synthesized on this fragment, and the amino acid that will be
transfer this tRNA during protein biosynthesis if the third triplet
corresponds to the tRNA anticodon. Explain the answer. To solve a task
use the genetic code table.

Solution:

This is a task for protein synthesis.

DNA: GCTTCCACTGTTCACA

tRNA: CGAAGG UGA CAAUGU

The third tRNA triplet is UGA. It corresponds to the mRNA codon - ACU.

According to the table of the genetic code, we determine that the amino acid Tre corresponds to the ACC codon.

Answer:

1) nucleotide sequence of the tRNA region: TsGAAGGUGATSAUGU;
2) the nucleotide sequence of the UGA anticodon (the third triplet) corresponds to the codon on the ACC mRNA;
3) according to the table of the genetic code, this codon corresponds to the TPE amino acid that this tRNA will carry

Early version of the Unified State Exam 2017 - task No. 27

It is known that all types of RNA are synthesized on a DNA template. The fragment of the DNA molecule on which the site of the central loop of tRNA is synthesized has the following nucleotide sequence: GAAGCTGTTTCGGACT. Set the nucleotide sequence of the tRNA site that is synthesized on this fragment, and the amino acid that this tRNA will transfer during protein biosynthesis, if the third triplet corresponds to the tRNA anticodon. Justify the sequence of your actions. To solve the task, use the table of the genetic code.

Solution:

This is a task for protein synthesis.

I present to you a variant of solving this problem in a draft, in the answer you need to write down only what is required.

DNA: GAAGCTGTTCGGACT

tRNA: CUU-CGA- CAA- HCC-UGA;

The third tRNA triplet is CAA . It corresponds to the mRNA codon - GUU.

According to the table of the genetic code, we determine that the amino acid Val corresponds to the codon GUU.

1) By the principle of complementarity based on DNA, we find the nucleotide sequence of tRNA

the nucleotide sequence of the tRNA region CUU-CGA-CAA-GCC-UGA;

2) the nucleotide sequence of the CAA anticodon (third triplet) corresponds to the codon on the GUU mRNA;

3) according to the table of the genetic code, this codon corresponds to the amino acid VAL (valine), which this tRNA will carry.

Note.

Answer:

1) the nucleotide sequence of the tRNA site: CUU-CGA- CAA- HCC-UGA;
2) the nucleotide sequence of the tRNA anticodon - CAA . It corresponds to the mRNA codon - GUU
3) according to the table of the genetic code, this codon corresponds to the amino acid Val, which this tRNA will carry

USE. Methodology for solving problems C-5 on the topic "Protein biosynthesis"

I have been a validation expert for several years USE works in biology. During the test, I encountered the problem of solving the task C-5 by students - tasks on the topic “Protein biosynthesis”. At first glance, everything is extremely simple, but why did many exam takers lose points on this particular task, having solved the problem incorrectly. In order to understand the problem, I propose two problems with a different type of solution. Examinees solve them in one image and likeness.

Task 1. An i-RNA chain fragment has a nucleotide sequence:

CCCACCCAGUA. Determine the nucleotide sequence on DNA, tRNA anticodons, and amino acid sequence in a protein fragment using the genetic code table.

Task 2. The DNA fragment has the following nucleotide sequence TTAGCCGATCCG. Set the nucleotide sequence of the t-RNA that is synthesized on this fragment and the amino acid that this t-RNA will carry if the third triplet corresponds to the t-RNA anticodon. To solve the problem, use the table of the genetic code.

Problem No. 1 is solved by the majority of students, because it corresponds to the sequence of biosynthesis stages, which can be represented as an image:

In problem 1, mRNA is known. Let's turn to the template.

The scheme for solving problem No. 1 includes:

1) DNA sequence: GGGTGGCGTCAT;

2) anticodons of tRNA molecules: GGG, UGG, CGU, CAU;

3) amino acid sequence (according to the table of the genetic code): pro-tre-ala-val.

If task number 2 is solved in the same sequence as the first one, then it will not be solved correctly. In order to solve this problem, it is necessary to remember the immutable rule: "All RNA is synthesized from DNA in the nucleus." In order to represent the sequence of ongoing processes, I propose a diagram:

Let us turn to the scheme: a linear t-RNA molecule is synthesized with DNA in the nucleus, leaves it and, thanks to complementary regions, acquires its characteristic shape - the shape of a trefoil. The template for solving this type of problem looks like this:

The scheme for solving problem No. 2 includes:

1) the composition of the t-RNA molecule: AAUCGGCUAGGC, the third triplet is CUA.

2) the CUA anticodon is complemented by the i-RNA triplet - GAU.

3) the GAU triplet encodes the amino acid asp (according to the genetic code table), which is carried by this t-RNA.

If the problem involves several t-RNAs, then it is solved according to the first type. If it is about one t-RNA, then the problem is solved according to the second type. Everything is very simple, the main thing is to imagine the sequence of processes, which can be facilitated by the proposed schemes.

Insert in the text "Protein biosynthesis" the missing terms from the proposed list, using numerals for this. Write down the numbers of the selected answers in the text, and then enter the resulting sequence of numbers (in the text) into the table below.

PROTEIN BIOSYNTHESIS

As a result of plastic metabolism, proteins specific to the organism are synthesized in cells. The section of DNA in which information about the structure of one protein is encoded is called ______(A). Protein biosynthesis begins

from the synthesis of ______ (B), and the assembly itself occurs in the cytoplasm with the participation of ______ (C). The first stage of protein biosynthesis is called _________(G), and the second is translation.

LIST OF TERMS:

3) transcription

4) mutation

6) ribosome

7) Golgi complex

8) phenotype

Write down the numbers in response, arranging them in the order corresponding to the letters:

A	B	IN	G

Explanation.

As a result of plastic metabolism, proteins specific to the organism are synthesized in cells. The section of DNA that encodes information about the structure of a single protein is called a gene. Protein biosynthesis begins with the synthesis of mRNA, and the assembly itself occurs in the cytoplasm with the participation of ribosomes. The first stage of protein biosynthesis is called transcription, and the second - translation.

Answer: 5163.

Answer: 5163

Source: RESHU OGE

All of the following features, except for two, can be used to describe the process of protein biosynthesis in a cell. Identify two features that “fall out” of the general list, and write down in response the numbers under which they are indicated.

1) The process occurs in the presence of enzymes.

2) The central role in the process belongs to RNA molecules.

3) The process is accompanied by the synthesis of ATP.

4) Amino acids serve as monomers for the formation of molecules.

5) The assembly of protein molecules is carried out in lysosomes.

Explanation.

IMPLEMENTATION OF HEREDITARY INFORMATION IN THE EUKARYOT CELL (PROTEIN SYNTHESIS):

1) rewriting information from DNA to mRNA (transcription) in the nucleus;

2) mRNA moves from the nucleus to the cytoplasm and binds with the 5'-end to the small subunit of the ribosome (later, with the attachment of the first tRNA to the mRNA, the large subunit of the ribosome also joins);

3) different tRNAs bind (activation of amino acids) with free amino acids of the cytoplasm (ATP energy is spent) and move them to the site of protein synthesis (to the ribosome);

4) tRNA anticodon binds to the corresponding (complementary) mRNA codon;

5) the amino acid attached to the tRNA binds by a peptide bond to the growing polypeptide chain;

6) tRNA released from the amino acid leaves the ribosome;

7) the ribosome moves one codon along the mRNA;

8) steps 4 to 7 are repeated several times until the protein is synthesized;

9) the synthesized protein is released from the ribosome.

(1) The process occurs in the presence of enzymes - protein biosynthesis;

(2) The central role in the process belongs to RNA molecules - protein biosynthesis;

(3) The process is accompanied by the synthesis of ATP - sign drops out(protein biosynthesis is accompanied by the breakdown of ATP);

(4) Monomers for the formation of molecules are amino acids - protein biosynthesis;

(5) The assembly of protein molecules is carried out in lysosomes - sign drops out(false statement, the assembly of protein molecules does not occur in lysosomes, but on ribosomes).

Answer: 35.

Answer: 35

Source: RESHU USE

What is the relationship energy metabolism and protein biosynthesis?

Explanation.

1) In the process of protein biosynthesis, the energy of ATP molecules synthesized in the process of energy metabolism is used.

2) Energy metabolism reactions involve enzymes formed as a result of protein biosynthesis.

3) The process of protein breakdown to amino acids is an intermediate stage of energy metabolism (from these amino acids, in the process of protein biosynthesis, the cell's own proteins are built).

Section: General biology. Metabolism

It is known that all types of RNA are synthesized on a DNA template.

A fragment of a DNA molecule, on which a section of the central loop of tRNA is synthesized, has the following nucleotide sequence (the upper strand is semantic, the lower strand is transcribed).

5'-AACCTTTTTTGCCTGA-3'

3'-TTGGAAAAAACGGACT-5'

Genetic code (mRNA)

First base	Second base				Third base
	At	C	A	G
At
C
A
G

Explanation.

DNA: 3'-TTH-GAA-AAA-CGG-ACT-5'

tRNA: 5'-AAC-CUU-UUU-GCC-UGA-3'

If the third triplet corresponds to the tRNA anticodon 5'- UUU-3' , to find the mRNA, we first record in the reverse order from 3' → to 5' we get 3'-UUU-5', determine the mRNA: 5 "-AAA-3".

3. According to the table of the genetic code, the codon 5 "-AAA-3" corresponds to the amino acid - Lys, which this tRNA will carry.

Note.

IN this type assignments keywords are: " all types of RNA are synthesized on a DNA template».

Section: Fundamentals of genetics

Source: RESHU USE

Which number in the figure indicates the stage of translation in the process of protein biosynthesis?

Explanation.

The stage of translation in the process of protein biosynthesis is indicated by the number 3.

1 (the figure is not visible in the figure - this is 1 arrow) - transcription; 2 - release of mRNA (mRNA) into the cytoplasm;

4 - protein termination - completion of polypeptide synthesis. Post-translational transformations of proteins.

Answer: 3

Source: Diagnostic work in biology 04/06/2011 Option 2.

Are the following statements about metabolic processes true?

A. The final oxidation of organic compounds to CO 2 and H 2 O occurs in the mitochondrial matrix.

B. Protein biosynthesis occurs in all membrane organelles of the cell.

1) only A is true

2) only B is true

3) both statements are correct

4) both judgments are wrong

Explanation.

Protein biosynthesis occurs in ribosomes (non-membrane organoid); in others, for example, lysosomes, there is no biosynthesis, which means that statement B is incorrect.

Oxidation to carbon dioxide occurs in the Krebs cycle, which occurs in the mitochondrial matrix.

Answer: 1

Natalya Evgenievna Bashtannik

In eukaryotes, all reactions of the Krebs cycle occur inside mitochondria, and the enzymes catalyzing them, except for one, are in a free state in the mitochondrial matrix, with the exception of succinate dehydrogenase, which is localized on the inner mitochondrial membrane, integrating into the lipid bilayer.

Madina Nikolaenko 13.06.2016 21:15

Statement b does not say that nothing happens in the non-membrane organelles of the cell. And membrane organelles have DNA and they synthesize their proteins.

Natalya Evgenievna Bashtannik

Not all membrane organelles have DNA, only two-membrane ones (mitochondria and plastids) have it.

Valentin Palimpsestov 25.10.2018 10:28

In the Krebs cycle, water is not released, and carbon dioxide is released during the formation of Acetyl-CoA, which then enters the cycle.

If the task had written: "in the mitochondria", then everything was fine. Or: "at the aerobic stage of catabolism." And it turns out that the answer is not entirely correct.

Protein biosynthetic reactions in which the sequence of triplets in mRNA provides the sequence of amino acids in the protein molecule are called

1) hydrolytic

2) matrix

3) enzymatic

4) oxidative

Explanation.

Synthesis reactions organic matter based on another organic molecule(matrices) are referred to as matrix synthesis reactions. Protein biosynthesis occurs on the basis of mRNA, which is a template during translation.

Answer: 2

It is known that all types of RNA are synthesized on a DNA template. A fragment of a DNA molecule, on which a section of the central loop of tRNA is synthesized, has the following nucleotide sequence (the upper strand is semantic, the lower strand is transcribed).

5'-CGAAGGTGACAATGT-3'

3'-HCTTTCCACCTGTTCA-5'

Set the nucleotide sequence of the tRNA section that is synthesized on this fragment, designate the 5' and 3' ends of this fragment and determine the amino acid that this tRNA will transfer during protein biosynthesis if the third triplet from the 5' end corresponds to the tRNA anticodon. Explain the answer. To solve the problem, use the table of the genetic code.

Genetic code (mRNA)

First base	Second base				Third base
	At	C	A	G
At
C
A
G

Rules for using the table

The first nucleotide in the triplet is taken from the left vertical row; the second - from the top horizontal row and the third - from the right vertical. Where the lines coming from all three nucleotides intersect, the desired amino acid is located.

Explanation.

The scheme for solving the problem includes:

1. Nucleotide sequence of a tRNA region ( the upper chain is semantic by condition):

2. Nucleotide sequence of anticodon UGA ( by condition the third triplet) matches the codon on the UCA mRNA;

3. According to the table of the genetic code, this codon corresponds to the amino acid -Ser, which this tRNA will carry.

Note.

1. Based on a fragment of a DNA molecule, we determine the nucleotide sequence of the tRNA site that is synthesized on this fragment.

DNA: 3'-HCT-TCC-ACT-GTT-ACA-5'

tRNA: 5'-CGA-AGG-UGA-CAA-UGU-3'

On DNA from the 3" end, tRNA is built from the 5" end.

2. We determine the mRNA codon that will be complementary to the tRNA triplet in the process of protein biosynthesis.

If the third triplet corresponds to the tRNA anticodon 5'-UGA-3', to find the mRNA, we first record in the reverse order from 3' → to 5' we get 3'-AGU-5', determine the mRNA: 5"-UCA-3".

3. According to the table of the genetic code, the codon 5 "-UCA-3" corresponds to the amino acid -Ser, which this tRNA will carry.

Explanation of the structure of DNA in the condition:

Double helix of DNA. Two antiparallel (5'-end of one chain is opposite the 3'-end of the other) complementary chains of polynucleotides connected by hydrogen bonds in pairs A-T and G-C, form a double-stranded DNA molecule. The DNA molecule is spirally twisted around its axis. There are approximately 10 base pairs per turn of DNA.

Semantic strand of DNA - The sequence of nucleotides in the chain encodes hereditary information.

The transcribed (antisense) strand is essentially a copy of the sense strand of DNA. Serves as a matrix for the synthesis of mRNA (information about the primary structure of the protein), tRNA, rRNA, regulatory RNA.

Source: Demo version of the USE-2020 in biology.

It is known that all types of RNA are synthesized on a DNA template. The fragment of the DNA molecule, on which the region of the central loop of tRNA is synthesized, has the following nucleotide sequence:

Genetic code (mRNA)

First base	Second base				Third base
	At	C	A	G
At
C
A
G

Rules for using the table

Explanation.

According to the principle of complementarity, on the basis of the template DNA chain, we determine the sequence of the tRNA region: 5 "- TsGAAGGUGATSAUGU - 3";

Note

Explanation of the structure of DNA in the condition:

Double helix of DNA. Two antiparallel (5'-end of one chain is opposite the 3'-end of the other) complementary chains of polynucleotides, connected by hydrogen bonds in pairs A-T and G-C, form a double-stranded DNA molecule.

Note.

That is, we need to find exactly tRNA - molecules consisting of 70-90 nucleotides, which are folded in a certain way and resemble a clover leaf in shape and carry amino acids in protein biosynthesis. They are synthesized on DNA in certain areas that are visible under a microscope in the form of nucleoli.

Therefore, first, on DNA, according to the principle of complementarity, we determine the tRNA site (just as we did when determining mRNA).

Then we find the triplet that is central, we translate it into mRNA according to the principle of complementarity, and only now we find the amino acid from the table of the genetic code.

It is known that all types of RNA are synthesized on a DNA template. The fragment of the DNA molecule, on which the central loop region of tRNA is synthesized, has the following nucleotide sequence:

Set the nucleotide sequence of the tRNA site that is synthesized on this fragment, and the amino acid that this tRNA will transfer during protein biosynthesis, if the third triplet corresponds to the tRNA anticodon. Explain the answer. To solve the problem, use the table of the genetic code.

Genetic code (mRNA)

First base	Second base				Third base
	At	C	A	G
At
C
A
G

Rules for using the table

Explanation.

1) According to the principle of complementarity, based on the template DNA chain, we determine the sequence of the tRNA region: 5 "- GUG-UAU-GAA-UHC-AUA - 3".

2) the nucleotide sequence of the GAA anticodon (third triplet) corresponds to the codon on the UUC mRNA;

Note

The mRNA codon is written in the orientation from the 5" end to the 3" end. The mRNA codon corresponds to the third tRNA triplet 5'-GAA-3', therefore, to find the mRNA, we first record in reverse order from 3' → to 5' and get 3'-AAG-5', then the mRNA in the direction 5 "→ 3" will be UUC.

3) according to the table of the genetic code, this codon corresponds to the Phen amino acid, which this tRNA will carry.

Explanation of the structure of DNA in the condition:

Semantic (coding) strand of DNA - The sequence of nucleotides in the chain encodes hereditary information.

The transcribed (antisense/template) strand is essentially a copy of the DNA sense strand. Serves as a matrix for the synthesis of mRNA (information about the primary structure of the protein), tRNA, rRNA, regulatory RNA.

Note.

In this type of tasks, the key words are: "all types of RNA are synthesized on a DNA template."

Therefore, first, on DNA, according to the principle of complementarity, we determine the tRNA site (just as we did when determining mRNA).

Then we find the triplet that is central, we translate it into mRNA according to the principle of complementarity, and only now we find the amino acid from the table of the genetic code.

It is known that all types of RNA are synthesized on a DNA template. The fragment of the DNA molecule on which the central loop region of tRNA is synthesized has the following nucleotide sequence: tRNA in the process of protein biosynthesis, if the third triplet corresponds to the tRNA anticodon. Justify the sequence of your actions. To solve the problem, use the table of the genetic code.

Rules for using the table

Explanation.

1) According to the principle of complementarity, on the basis of the template DNA chain, we find the nucleotide sequence of tRNA: 5" - CUUUCCAGCAAGCCUGA - 3".

2) the nucleotide sequence of the CAA anticodon (the third triplet) corresponds to the codon on the UUG mRNA;

Note

The mRNA codon is written in the orientation from the 5" end to the 3" end. The mRNA codon corresponds to the third triplet of tRNA 5'-CAA-3', therefore, to find the mRNA, we first record in reverse order from 3' → to 5' and get 3'-AAC-5', then the mRNA in the direction 5 "→ 3" will be UUG.

3) according to the table of the genetic code, this codon corresponds to the amino acid Leu (leucine), which this tRNA will carry.

Explanation of the structure of DNA in the condition:

Semantic (coding) strand of DNA - The sequence of nucleotides in the chain encodes hereditary information.

Note.

In this type of tasks, the key words are: "all types of RNA are synthesized on a DNA template."

Therefore, first, on DNA, according to the principle of complementarity, we determine the tRNA site (just as we did when determining mRNA).

Then we find the triplet that is central, we translate it into mRNA according to the principle of complementarity, and only now we find the amino acid from the table of the genetic code.

It is known that all types of RNA are synthesized on a DNA template. The fragment of the DNA molecule, on which the central loop region of tRNA is synthesized, has the following nucleotide sequence:

Genetic code (mRNA)

First base	Second base				Third base
	At	C	A	G
At
C
A
G

Rules for using the table

Explanation.

1) According to the principle of complementarity, on the basis of the template DNA chain, we determine the sequence of the tRNA region: 5 "- HCAACCCGAUCCAA - 3";

2) the nucleotide sequence of the CGA anticodon (third triplet) corresponds to the codon on the UCG mRNA;

Note

The mRNA codon is written in the orientation from the 5" end to the 3" end. The mRNA codon corresponds to the third triplet of tRNA 5'-CHA-3', therefore, to find the mRNA, we first record in reverse order from 3' → to 5' and get 3'-AHC-5', then the mRNA in the direction 5 "→ 3" will be UCG.

3) according to the table of the genetic code, this codon corresponds to the amino acid Ser, which this tRNA will carry.

Explanation of the structure of DNA in the condition:

Semantic (coding) strand of DNA - The sequence of nucleotides in the chain encodes hereditary information.

Note.

In this type of tasks, the key words are: "all types of RNA are synthesized on a DNA template."

Therefore, first, on DNA, according to the principle of complementarity, we determine the tRNA site (just as we did when determining mRNA).

Then we find the triplet that is central, we translate it into mRNA according to the principle of complementarity, and only now we find the amino acid from the table of the genetic code.

It is known that all types of RNA are synthesized on a DNA template. The fragment of the DNA molecule on which the central loop region of tRNA is synthesized has the following nucleotide sequence: 5" - CGAAGGTGACAATGT - 3" 3" - HCTTCCACTGTTCACA - 5" Set the nucleotide sequence of the tRNA region that is synthesized on this fragment and the amino acid that this tRNA in the process of protein biosynthesis, if the third triplet corresponds to the tRNA anticodon. Explain the answer. To solve the problem, use the table of the genetic code.

Rules for using the table

Explanation.

1) According to the principle of complementarity, on the basis of the template DNA chain, we determine the sequence of the tRNA region: 5 "- TsGAAGGUGATSAUGU - 3";

2) the nucleotide sequence of the UGA anticodon (third triplet) corresponds to the codon on the UCA mRNA;

Note

The mRNA codon is written in the orientation from the 5" end to the 3" end. The mRNA codon corresponds to the third triplet of tRNA 5'-UGA-3', therefore, to find the mRNA, we first record in reverse order from 3' → to 5' and get 3'-AGU-5', then the mRNA in the direction 5 "→ 3" will be UCA.

3) according to the table of the genetic code, this codon corresponds to the amino acid Ser, which this tRNA will carry.

Explanation of the structure of DNA in the condition:

Semantic (coding) strand of DNA - The sequence of nucleotides in the chain encodes hereditary information.

Note.

In this type of tasks, the key words are: "all types of RNA are synthesized on a DNA template."

Therefore, first, on DNA, according to the principle of complementarity, we determine the tRNA site (just as we did when determining mRNA).

Then we find the triplet that is central, we translate it into mRNA according to the principle of complementarity, and only now we find the amino acid from the table of the genetic code.

5" - ATSGGGTAAGTSAATGTS - 3"

3" - TGCCATTTCGTTACG - 5" Set the nucleotide sequence of the tRNA region that is synthesized on this fragment, and the amino acid that this tRNA will transfer during protein biosynthesis, if the third triplet corresponds to the tRNA anticodon. Explain the answer. To solve the problem, use the table of the genetic code.

Genetic code (mRNA)

First base	Second base				Third base
	At	C	A	G
At
C
A
G

Rules for using the table

The first nucleotide in the triplet is taken from the left vertical row; the second - from the upper horizontal row; the third - from the right vertical. Where the lines coming from all three nucleotides intersect, the desired amino acid is located.

Explanation.

1) According to the principle of complementarity, on the basis of the template DNA chain, we determine the sequence of the tRNA region: 5 "- ACGGGUAAGCAAUGC - 3";

2) the nucleotide sequence of the AAG anticodon (third triplet) corresponds to the codon on the CUU mRNA;

Note

The mRNA codon is written in the orientation from the 5" end to the 3" end. The mRNA codon corresponds to the third triplet of tRNA 5'-AAG-3', therefore, to find the mRNA, we first record in reverse order from 3' → to 5' and get 3'-GAA-5', then the mRNA in the direction 5 "→ 3" will be CUU.

Explanation of the structure of DNA in the condition:

Semantic (coding) strand of DNA - The sequence of nucleotides in the chain encodes hereditary information.

Note.

In this type of tasks, the key words are: "all types of RNA are synthesized on a DNA template."

Therefore, first, on DNA, according to the principle of complementarity, we determine the tRNA site (just as we did when determining mRNA).

Then we find the triplet that is central, we translate it into mRNA according to the principle of complementarity, and only now we find the amino acid from the table of the genetic code.

It is known that all types of RNA are synthesized on a DNA template. The fragment of the DNA chain on which the central loop of tRNA is synthesized has the following nucleotide sequence:

5" - TGTSATTAATSGATAG - 3"

3" - ACGGTAATTHCTATC - 5" Set the nucleotide sequence of the tRNA region that is synthesized on this fragment, and the amino acid that this tRNA will transfer during protein biosynthesis, if the third triplet corresponds to the tRNA anticodon. Explain the answer. To solve the problem, use the table of the genetic code.

Genetic code (mRNA)

First base	Second base				Third base
	At	C	A	G
At
C
A
G

Rules for using the table

Explanation.

1) According to the principle of complementarity, on the basis of the template DNA chain, we determine the sequence of the tRNA region: 5 "- UGTSAUUAACGAUAG - 3";

2) the nucleotide sequence of the UAA anticodon (third triplet) corresponds to the codon on the UUA mRNA;

Note

The mRNA codon is written in the orientation from the 5" end to the 3" end. The mRNA codon corresponds to the third tRNA triplet 5'-UAA-3', therefore, to find the mRNA, we first write in reverse order from 3' → to 5' and get 3'-AAU-5', then the mRNA in the direction 5 "→ 3" will be wow.

3) according to the table of the genetic code, this codon corresponds to the amino acid Leu, which this tRNA will carry.

Explanation of the structure of DNA in the condition:

Semantic (coding) strand of DNA - The sequence of nucleotides in the chain encodes hereditary information.

Note.

In this type of tasks, the key words are: "all types of RNA are synthesized on a DNA template."

Therefore, first, on DNA, according to the principle of complementarity, we determine the tRNA site (just as we did when determining mRNA).

Then we find the triplet that is central, we translate it into mRNA according to the principle of complementarity, and only now we find the amino acid from the table of the genetic code.

It is known that all types of RNA are synthesized on a DNA template. The fragment of the DNA chain on which the tRNA central loop region is synthesized has the following nucleotide sequence: 5" - AGGCGTATGCTATCC - 3" 3" - TTCGCATATSGATAGG - 5" Set the nucleotide sequence of the tRNA segment that is synthesized on this fragment and the amino acid that this fragment will carry tRNA during protein biosynthesis if the third triplet is a tRNA anticodon. Explain the answer. To solve the problem, use the table of the genetic code.

Genetic code (mRNA)

First base	Second base				Third base
	At	C	A	G
At
C
A
G

Rules for using the table

The first nucleotide in the triplet is taken from the left vertical row, the second from the top horizontal row, and the third from the right vertical row. Where the lines coming from all three nucleotides intersect, the desired amino acid is located.

Explanation.

1) Based on the principle of complementarity, on the basis of the template DNA chain, we determine the sequence of the tRNA region: 5 "- AGGTSGUAUGCUAUCC - 3".

2) the nucleotide sequence of the anticodon AUG (the third triplet) corresponds to the codon on the CAU mRNA;

Note

The mRNA codon is written in the orientation from the 5" end to the 3" end. The mRNA codon corresponds to the third triplet of tRNA 5'-AUG-3', therefore, to find the mRNA, we first record in reverse order from 3' → to 5' and get 3'-GUA-5', then the mRNA in the direction 5 "→ 3" will be CAU.

3) according to the table of the genetic code, this codon corresponds to the amino acid His, which this tRNA will carry.

Explanation of the structure of DNA in the condition:

Semantic (coding) strand of DNA - The sequence of nucleotides in the chain encodes hereditary information.

Note.

In this type of tasks, the key words are: "all types of RNA are synthesized on a DNA template."

Therefore, first, on DNA, according to the principle of complementarity, we determine the tRNA site (just as we did when determining mRNA).

Then we find the triplet that is central, we translate it into mRNA according to the principle of complementarity, and only now we find the amino acid from the table of the genetic code.

5" - TATTSGATTGTTGA - 3"

3" - ATAGCTGAACGGACT - 5" Set the nucleotide sequence of the tRNA region that is synthesized on this fragment, and the amino acid that this tRNA will transfer during protein biosynthesis, if the third triplet corresponds to the tRNA anticodon. Explain the answer. To solve the problem, use the table of the genetic code.

Genetic code (mRNA)

First base	Second base				Third base
	At	C	A	G
At
C
A
G

Rules for using the table

Explanation.

1) According to the principle of complementarity, on the basis of the template DNA chain, we determine the sequence of the tRNA region: 5 "- UAUTSGATSUUGCCUGA - 3";

Note

Explanation of the structure of DNA in the condition:

Semantic (coding) strand of DNA - The sequence of nucleotides in the chain encodes hereditary information.

Note.

In this type of tasks, the key words are: "all types of RNA are synthesized on a DNA template."

Therefore, first, on DNA, according to the principle of complementarity, we determine the tRNA site (just as we did when determining mRNA).

Then we find the triplet that is central, we translate it into mRNA according to the principle of complementarity, and only now we find the amino acid from the table of the genetic code.

Genetic code (mRNA)

First base	Second base				Third base
	At	C	A	G
At
C
A
G

Explanation.

1) According to the principle of complementarity, on the basis of the template DNA chain, we determine the sequence of the tRNA region: 5 "- UAUTSGATSUUGCCUGA - 3".

2) the nucleotide sequence of the CUU anticodon (third triplet) corresponds to the codon on the AAG mRNA;

Note

The mRNA codon is written in the orientation from the 5" end to the 3" end. The mRNA codon corresponds to the third tRNA triplet 5'-CUU-3', therefore, to find the mRNA, we first record in reverse order from 3' → to 5' and get 3'-UUC-5', then the mRNA in the direction 5 "→ 3" will be AAG.

3) according to the table of the genetic code, this codon corresponds to the amino acid Lys, which this tRNA will carry.

Explanation of the structure of DNA in the condition:

Semantic (coding) strand of DNA - The sequence of nucleotides in the chain encodes hereditary information.

Note.

In this type of tasks, the key words are: "all types of RNA are synthesized on a DNA template."

Genetic code (mRNA)

First base	Second base				Third base
	At	C	A	G
At
C
A
G

Rules for using the table

The first nucleotide in the triplet is taken from the left vertical row, the second from the upper horizontal row, and the third from the right vertical row. Where the lines coming from all three nucleotides intersect, and the desired amino acid is located

Explanation.

1) the nucleotide sequence of the tRNA region UAUCGATSUUGCCUGA;

2) the nucleotide sequence of the CUU anticodon (the third triplet) corresponds to the codon on the GAA mRNA;

3) according to the table of the genetic code, this codon corresponds to the GLU amino acid that this tRNA will carry.

Note.

In this type of tasks, the key words are: "all types of RNA are synthesized on a DNA template."

Therefore, first, on DNA, according to the principle of complementarity, we determine the tRNA site (just as we did when determining mRNA).

Then we find the triplet that is central, we translate it into mRNA according to the principle of complementarity, and only now we find the amino acid from the table of the genetic code.

1) tRNA sequence - AUA GCU GAA CGG ACU; 2) mRNA codon - CUU, 3) amino acid - LEI. As the guest wrote earlier.

If we are wrong, please explain why you got a different solution after all

Natalya Evgenievna Bashtannik

This is a different type of task!

1. Read the task again! Key phrase: It is known that all types of RNA are synthesized on a DNA template.

2. There is tRNA in the cytoplasm. Where is she from? YES! ALSO is synthesized on the DNA template, as well as mRNA. Therefore, the principle of action is the same, but we find the tRNA chain according to the principle of complementarity. DNA is tRNA.

3. And then we are already looking for the triplet that is the anticode (there may be different variations of the task).

Genetic code (mRNA)

First base	Second base				Third base
	At	C	A	G
At
C
A
G

Rules for using the table

Explanation.

1) Synthesized tRNA - ACGGGUAAGCAAUGC (according to the principle of complementarity based on the indicated DNA chain)

2) Since the anticodon of tRNA is the third triplet - AAG by condition, then the codon on mRNA is UUC

3) Using the table of the genetic code, we determine that the codon on mRNA - UUC - encodes the amino acid PEN

Note.

In this type of tasks, the key words are: "all types of RNA are synthesized on a DNA template."

Therefore, first, on DNA, according to the principle of complementarity, we determine the tRNA site (just as we did when determining mRNA).

Then we find the triplet that is central, we translate it into mRNA according to the principle of complementarity, and only now we find the amino acid from the table of the genetic code.

In the body's metabolism the leading role belongs to proteins and nucleic acids.

Protein substances form the basis of all vital cell structures, have an unusually high reactivity, and are endowed with catalytic functions.

Nucleic acids are part of the most important organ of the cell - the nucleus, as well as the cytoplasm, ribosomes, mitochondria, etc. Nucleic acids play an important, primary role in heredity, body variability, and protein synthesis.

Synthesis plan protein is stored in the nucleus of the cell directly synthesis occurs outside the nucleus, so it is necessary help to deliver the encoded plan from the kernel to the site of synthesis. Such help rendered by RNA molecules.

The process starts in the cell nucleus: part of the DNA "ladder" unwinds and opens. Due to this, the RNA letters form bonds with the open DNA letters of one of the DNA strands. The enzyme transfers the letters of the RNA to connect them into a thread. So the letters of DNA are "rewritten" into the letters of RNA. The newly formed RNA chain is separated, and the DNA "ladder" twists again.

After further modifications, this kind of encoded RNA is ready.

RNA comes out of the nucleus and goes to the site of protein synthesis, where the letters of the RNA are deciphered. Each set of three RNA letters forms a "word" that stands for one particular amino acid.

Another type of RNA looks for this amino acid, captures it with the help of an enzyme, and delivers it to the site of protein synthesis. As the RNA message is read and translated, the chain of amino acids grows. This chain twists and folds into a unique shape, creating one kind of protein.
Even the process of protein folding is remarkable: it would take 1027 years to calculate all the folding possibilities of a medium-sized protein consisting of 100 amino acids using a computer. And for the formation of a chain of 20 amino acids in the body, it takes no more than one second - and this process occurs continuously in all cells of the body.

Genes, genetic code and its properties.

About 7 billion people live on Earth. Except for 25-30 million pairs of identical twins, then genetically all people are different: each is unique, has unique hereditary characteristics, character traits, abilities, temperament.

Such differences are explained differences in genotypes- sets of genes of an organism; each one is unique. The genetic traits of a particular organism are embodied in proteins- consequently, the structure of the protein of one person differs, although quite a bit, from the protein of another person.

It does not mean that humans do not have exactly the same proteins. Proteins that perform the same functions may be the same or very slightly differ by one or two amino acids from each other. But there are no people on Earth (with the exception of identical twins) in whom all proteins would be the same.

Information about the primary structure of a protein encoded as a sequence of nucleotides in a section of a DNA molecule - gene - a unit of hereditary information of an organism. Each DNA molecule contains many genes. The totality of all the genes of an organism makes up its genotype .

Hereditary information is encoded using genetic code , which is universal for all organisms and differs only in the alternation of nucleotides that form genes and code for proteins of specific organisms.

Genetic code comprises triplets (triplets) of nucleotides DNA that combines in different sequences(AAT, HCA, ACH, THC, etc.), each of which encodes a certain amino acid(which will be built into the polypeptide chain).

Amino acids 20, A opportunities for combinations of four nucleotides in groups of three - 64 four nucleotides is enough to code for 20 amino acids

That's why one amino acid can be encoded several triplets.

Some of the triplets do not code for amino acids at all, but Launches or stops protein biosynthesis.

Actually code counts sequence of nucleotides in an i-RNA molecule, because it removes information from DNA (the process transcriptions) and translates it into a sequence of amino acids in the molecules of synthesized proteins (process broadcasts).

The composition of mRNA includes ACGU nucleotides, the triplets of which are called codons: the triplet on CHT DNA on mRNA will become the HCA triplet, and the AAG DNA triplet will become the UUC triplet.

Exactly i-RNA codons reflects the genetic code in the record.

Thus, genetic code - a unified system for recording hereditary information in nucleic acid molecules in the form of a sequence of nucleotides. Genetic code based on the use of an alphabet consisting of only four nucleotide letters that differ in nitrogenous bases: A, T, G, C.

Basic properties of the genetic code :

1. The genetic code is triplet. A triplet (codon) is a sequence of three nucleotides that codes for one amino acid. Since proteins contain 20 amino acids, it is obvious that each of them cannot be encoded by one nucleotide (since there are only four types of nucleotides in DNA, in this case 16 amino acids remain uncoded). Two nucleotides for coding amino acids are also not enough, since in this case only 16 amino acids can be encoded. This means that the smallest number of nucleotides encoding one amino acid is three. (In this case, the number of possible nucleotide triplets is 4 3 = 64).

2. Redundancy (degeneracy) The code is a consequence of its triplet nature and means that one amino acid can be encoded by several triplets (since there are 20 amino acids, and there are 64 triplets), with the exception of methionine and tryptophan, which are encoded by only one triplet. In addition, some triplets perform specific functions: in the mRNA molecule, the triplets UAA, UAG, UGA are terminating codons, i.e., stop signals that stop the synthesis of the polypeptide chain. The triplet corresponding to methionine (AUG), standing at the beginning of the DNA chain, does not encode an amino acid, but performs the function of initiating (exciting) reading.

3. Along with redundancy, the code has the property uniqueness: each codon corresponds to only one specific amino acid.

4. The code is collinear, those. The sequence of nucleotides in a gene exactly matches the sequence of amino acids in a protein.

5. The genetic code is non-overlapping and compact, i.e. does not contain "punctuation marks". This means that the reading process does not allow for the possibility of overlapping columns (triples), and, starting at a certain codon, the reading goes continuously triple by triple up to stop signals ( termination codons).

6. The genetic code is universal, i.e., the nuclear genes of all organisms encode information about proteins in the same way, regardless of the level of organization and systematic position these organisms.

Exist genetic code tables for deciphering i-RNA codons and building chains of protein molecules.

Matrix synthesis reactions.

In living systems, there are reactions unknown in inanimate nature - reactions matrix synthesis .

The term "matrix"in technology, they denote the form used for casting coins, medals, typographic font: the hardened metal exactly reproduces all the details of the form used for casting. Matrix synthesis resembles a casting on a matrix: new molecules are synthesized in strict accordance with the plan laid down in the structure of already existing molecules.

The matrix principle lies at the core the most important synthetic reactions of the cell, such as the synthesis of nucleic acids and proteins. In these reactions, an exact, strictly specific sequence of monomeric units in the synthesized polymers is provided.

This is where directional pulling monomers to a specific location cells - into molecules that serve as a matrix where the reaction takes place. If such reactions occurred as a result of a random collision of molecules, they would proceed infinitely slowly. The synthesis of complex molecules based on the matrix principle is carried out quickly and accurately.

The role of the matrix macromolecules of nucleic acids DNA or RNA play in matrix reactions.

monomeric molecules, from which the polymer is synthesized - nucleotides or amino acids - in accordance with the principle of complementarity are arranged and fixed on the matrix in a strictly defined, predetermined order.

Then comes "crosslinking" of monomer units into a polymer chain, and the finished polymer is dropped from the matrix.

After that matrix ready to the assembly of a new polymer molecule. It is clear that just as only one coin, one letter can be cast on a given mold, so only one polymer can be "assembled" on a given matrix molecule.

Matrix type of reactions- a specific feature of the chemistry of living systems. They are the basis of the fundamental property of all living things - its ability to replicate.

TO matrix synthesis reactions include:

1. DNA replication - the process of self-duplication of the DNA molecule, carried out under the control of enzymes. On each of the DNA strands formed after the breaking of hydrogen bonds, with the participation of the enzyme DNA polymerase, a daughter strand of DNA is synthesized. The material for synthesis is free nucleotides present in the cytoplasm of cells.

The biological meaning of replication lies in the exact transfer of hereditary information from the parent molecule to the daughter ones, which normally occurs during the division of somatic cells.

The DNA molecule consists of two complementary strands. These chains are held together by weak hydrogen bonds that can be broken by enzymes.

The molecule is capable of self-doubling (replication), and on each old half of the molecule a new half of it is synthesized.

In addition, an mRNA molecule can be synthesized on a DNA molecule, which then transfers the information received from DNA to the site of protein synthesis.

Information transfer and protein synthesis follow a matrix principle, comparable to the work of a printing press in a printing house. Information from DNA is copied over and over again. If errors occur during copying, they will be repeated in all subsequent copies.

True, some errors in copying information by a DNA molecule can be corrected - the process of eliminating errors is called reparations. The first of the reactions in the process of information transfer is the replication of the DNA molecule and the synthesis of new DNA strands.

2. transcription - synthesis of i-RNA on DNA, the process of removing information from a DNA molecule synthesized on it by an i-RNA molecule.

I-RNA consists of one strand and is synthesized on DNA in accordance with the rule of complementarity with the participation of an enzyme that activates the beginning and end of the synthesis of the i-RNA molecule.

The finished mRNA molecule enters the cytoplasm on the ribosomes, where the synthesis of polypeptide chains takes place.

3. broadcast - protein synthesis on i-RNA; the process of translating the information contained in the nucleotide sequence of an mRNA into the sequence of amino acids in a polypeptide.

4 .synthesis of RNA or DNA from RNA viruses

The sequence of matrix reactions during protein biosynthesis can be represented as scheme:

untranscribed strand of DNA	A T G	G G C	T A T
transcribed DNA strand	T A C	C C G	A T A
DNA transcription
mRNA codons	A U G	G G C	U A U
mRNA translation
tRNA anticodons	U A C	C C G	A U A
protein amino acids	methionine	glycine	tyrosine

Thus, protein biosynthesis- this is one of the types of plastic exchange, during which the hereditary information encoded in the DNA genes is realized in a certain sequence of amino acids in protein molecules.

Protein molecules are essentially polypeptide chains made up of individual amino acids. But amino acids are not active enough to connect with each other on their own. Therefore, before they combine with each other and form a protein molecule, amino acids must activate. This activation occurs under the action of special enzymes.

As a result of activation, the amino acid becomes more labile and under the action of the same enzyme binds to tRNA. Each amino acid corresponds strictly specific tRNA, which finds"own" amino acid and endures it into the ribosome.

Therefore, the ribosome receives various activated amino acids linked to their tRNAs. The ribosome is like conveyor to assemble a protein chain from various amino acids entering it.

Simultaneously with t-RNA, on which its own amino acid "sits", " signal" from the DNA contained in the nucleus. In accordance with this signal, one or another protein is synthesized in the ribosome.

The directing influence of DNA on protein synthesis is not carried out directly, but with the help of a special intermediary - matrix or messenger RNA (mRNA or i-RNA), which synthesized in the nucleus under the influence of DNA, so its composition reflects the composition of DNA. The RNA molecule is, as it were, a cast from the form of DNA. The synthesized mRNA enters the ribosome and, as it were, transfers it to this structure plan- in what order should the activated amino acids entering the ribosome be combined with each other in order to synthesize a certain protein. Otherwise, genetic information encoded in DNA is transferred to mRNA and then to protein.

The mRNA molecule enters the ribosome and flashes her. That segment of it that is currently in the ribosome is determined codon (triplet), interacts in a completely specific way with a structure suitable for it triplet (anticodon) in the transfer RNA that brought the amino acid into the ribosome.

Transfer RNA with its own amino acid fits to a specific mRNA codon and connects with him; to the next, neighboring site of i-RNA attaches another tRNA another amino acid and so on until the entire i-RNA chain is read, until all the amino acids are strung in the appropriate order, forming a protein molecule.

And t-RNA, which delivered the amino acid to a specific site of the polypeptide chain, freed from its amino acid and exits the ribosome.

Then again in the cytoplasm the desired amino acid can join it, and it again endure it into the ribosome.

In the process of protein synthesis, not one, but several ribosomes, polyribosomes, are simultaneously involved.

The main stages of the transfer of genetic information:

synthesis on DNA as on an i-RNA template (transcription)

synthesis in the ribosomes of the polypeptide chain according to the program contained in the i-RNA (translation).

The stages are universal for all living beings, but the temporal and spatial relationships of these processes differ in pro- and eukaryotes.

At eukaryote transcription and translation are strictly separated in space and time: the synthesis of various RNAs occurs in the nucleus, after which the RNA molecules must leave the nucleus, passing through the nuclear membrane. Then, in the cytoplasm, RNA is transported to the site of protein synthesis - ribosomes. Only after that comes the next stage - translation.

In prokaryotes, transcription and translation occur simultaneously.

Thus,

the place of synthesis of proteins and all enzymes in the cell are ribosomes - it's like "factories" protein, as it were, an assembly shop, where all the materials necessary to assemble the polypeptide chain of a protein from amino acids are supplied. The nature of the synthesized protein depends on the structure of the i-RNA, on the order of the nucleoids in it, and the structure of the i-RNA reflects the structure of the DNA, so that in the end the specific structure of the protein, i.e. the order of the various amino acids in it, depends on the order of the nucleoids in the DNA from the structure of DNA.

The stated theory of protein biosynthesis was called matrix theory. Matrix this theory called because, What nucleic acids play, as it were, the role of matrices in which all information is recorded regarding the sequence of amino acid residues in a protein molecule.

Creation of the matrix theory of protein biosynthesis and decoding of the amino acid code is the greatest scientific achievement of the 20th century, the most important step towards elucidating the molecular mechanism of heredity.

Thematic tasks

A1. Which of the statements is incorrect?

1) the genetic code is universal

2) the genetic code is degenerate

3) the genetic code is individual

4) the genetic code is triplet

A2. One DNA triplet encodes:

1) the sequence of amino acids in a protein

2) one sign of the organism

3) one amino acid

4) several amino acids

A3. "Punctuation marks" of the genetic code

1) start protein synthesis

2) stop protein synthesis

3) encode certain proteins

4) encode a group of amino acids

A4. If in a frog the amino acid VALIN is encoded by the GU triplet, then in a dog this amino acid can be encoded by triplets:

1) GUA and GUG

2) UUC and UCA

3) CCU and CUA

4) UAG and UGA

A5. Protein synthesis is completed at the moment

1) codon recognition by anticodon

2) receipt of i-RNA on ribosomes

3) the appearance of a "punctuation mark" on the ribosome

4) amino acid attachment to tRNA

A6. Specify a pair of cells in which one person contains different genetic information?

1) liver and stomach cells

2) neuron and leukocyte

3) muscle and bone cells

4) tongue cell and egg

A7. The function of i-RNA in the process of biosynthesis

1) storage of hereditary information

2) transport of amino acids to ribosomes

3) transfer of information to ribosomes

4) acceleration of the biosynthesis process

A8. The tRNA anticodon consists of UCG nucleotides. Which DNA triplet is complementary to it?