Recommendations for solving tasks C5 (molecular biology). Problems in molecular biology A polypeptide consists of 20

It's no secret that in order to maintain vital functions at a high level, a person needs protein - a kind of building material for body tissues; Proteins contain 20 amino acids, the names of which are unlikely to mean anything to the average office worker. Every person, especially if we talk about women, has at least once heard about collagen and keratin - these are proteins that are responsible for the appearance of nails, skin and hair.

Amino acids - what are they?

Amino acids (or aminocarboxylic acids; AMK; peptides) are organic compounds consisting of 16% amines - organic derivatives of ammonium - which distinguishes them from carbohydrates and lipids. They participate in the biosynthesis of protein by the body: in the digestive system, under the influence of enzymes, all proteins supplied with food are destroyed to AMC. In total, there are about 200 peptides in nature, but only 20 basic amino acids are involved in the construction of the human body, which are divided into replaceable and essential; sometimes there is a third type - semi-replaceable (conditionally replaceable).

Nonessential amino acids

Replaceable amino acids are those that are both consumed in food and reproduced directly in the human body from other substances.

• Alanine is a monomer of biological compounds and proteins. It carries out one of the main pathways of glucogenesis, that is, it is converted into glucose in the liver, and vice versa. A highly active participant in metabolic processes in the body.
• Arginine is an amino acid that can be synthesized in the body of an adult, but is not capable of synthesis in the body of a child. Promotes the production of growth hormones and others. The only carrier of nitrogenous compounds in the body. Helps increase muscle mass and reduce fat mass.
• Asparagine is a peptide involved in nitrogen metabolism. During the reaction with the enzyme asparaginase, it splits off ammonia and turns into aspartic acid.
• Aspartic acid - takes part in the creation of immunoglobulin, deactivates ammonia. Necessary for malfunctions of the nervous and cardiovascular systems.
• Histidine - used for the prevention and treatment of gastrointestinal diseases; has positive dynamics in the fight against AIDS. Protects the body from the harmful effects of stress.
• Glycine is a neurotransmitter amino acid. Used as a mild sedative and antidepressant. Enhances the effect of some nootropic drugs.
• Glutamine - in large quantities Activator of tissue repair processes.
• Glutamic acid - has a neurotransmitter effect and also stimulates metabolic processes in the central nervous system.
• Proline is one of the components of almost all proteins. They are especially rich in elastin and collagen, which are responsible for skin elasticity.
• Serine is an amino acid that is found in neurons of the brain and also contributes to the release of large amounts of energy. It is a derivative of glycine.
• Tyrosine is a component of animal and plant tissues. Can be reproduced from phenylalanine by the action of the enzyme phenylalanine hydroxylase; the reverse process does not occur.
• Cysteine ​​is one of the components of keratin, which is responsible for the firmness and elasticity of hair, nails, and skin. It is also an antioxidant. Can be produced from serine.

Amino acids that cannot be synthesized in the body are essential

Essential amino acids are those that cannot be generated in the human body and can only be supplied through food.

• Valine is an amino acid found in almost all proteins. Increases muscle coordination and reduces the body's sensitivity to temperature changes. Maintains the hormone serotonin at high levels.
• Isoleucine is a natural anabolic steroid that, through the process of oxidation, saturates muscle and brain tissue with energy.
• Leucine is an amino acid that improves metabolism. It is a kind of “builder” of protein structure.
• These three AMKs are part of the so-called BCAA complex, which is especially in demand among athletes. Substances in this group act as a source for increasing muscle mass, reducing fat mass and maintaining good health during particularly intense physical activity.
• Lysine is a peptide that accelerates tissue regeneration, the production of hormones, enzymes and antibodies. Responsible for the strength of blood vessels, found in muscle protein and collagen.
• Methionine - takes part in the synthesis of choline, the lack of which can lead to increased accumulation of fat in the liver.
• Threonine - gives elasticity and strength to tendons. It has a very positive effect on the heart muscle and tooth enamel.
• Tryptophan - supports emotional state, as it is converted into serotonin in the body. Indispensable for depression and other psychological disorders.
• Phenylalanine - improves the appearance of the skin by normalizing pigmentation. Supports psychological well-being by improving mood and bringing clarity to thinking.

Other methods for classifying peptides

Scientifically, the 20 essential amino acids are divided based on the polarity of their side chains, or radicals. Thus, four groups are distinguished: (but not having a charge), positively charged and negatively charged.

Non-polar are: valine, alanine, leucine, isoleucine, methionine, glycine, tryptophan, phenylalanine, proline. In turn, polar acids that have a negative charge include aspartic and glutamic acids. Polar, having a positive charge, are called arginine, histidine, lysine. Amino acids that have polarity but do not have a charge include cysteine, glutamine, serine, tyrosine, threonine, and asparagine.

20 amino acids: formulas (table)

Amino acid	Abbreviation
Asparagine
Aspartic acid
Histidine
Glutamine
Glutamic acid
Isoleucine
Methionine
Tryptophan
Phenylalanine

Based on this, it can be noted that all 20 in the table above) contain carbon, hydrogen, nitrogen and oxygen.

Amino acids: participation in cell activity

Aminocarboxylic acids are involved in the biological synthesis of protein. Protein biosynthesis is the process of modeling a polypeptide (“poly” - many) chain of amino acid residues. The process takes place on the ribosome, an organelle inside the cell that is directly responsible for biosynthesis.

Information is read from a section of the DNA chain according to the principle of complementarity (A-T, C-G); when creating m-RNA (messenger RNA, or i-RNA - information RNA - identical concepts), the nitrogenous base thymine is replaced by uracil. Then, using the same principle, a transporting amino acid molecules to the place of synthesis is created. T-RNA is encoded by triplets (codons) (example: UAU), and if you know what nitrogenous bases a triplet is represented by, you can find out which amino acid it carries.

Food groups with the highest AMK content

Dairy products and eggs contain important substances such as valine, leucine, isoleucine, arginine, tryptophan, methionine and phenylalanine. Fish and white meat have a high content of valine, leucine, isoleucine, histidine, methionine, lysine, phenylalanine, tryptophan. Legumes, grains and cereals are rich in valine, leucine, isoleucine, tryptophan, methionine, threonine, methionine. Nuts and various seeds will saturate the body with threonine, isoleucine, lysine, arginine and histidine.

Below is the amino acid content of some foods.

The largest amount of tryptophan and methionine can be found in hard cheese, lysine - in rabbit meat, valine, leucine, isoleucine, threonine and phenylalanine - in soy. When creating a diet based on maintaining normal BUN, you should pay attention to squid and peas, while the poorest in terms of peptide content are potatoes and cow's milk.

Lack of amino acids in vegetarianism

It is a myth that there are amino acids that are found exclusively in animal products. Moreover, scientists have found that plant protein is absorbed by the human body better than animal protein. However, when choosing vegetarianism as a lifestyle, it is very important to monitor your diet. The main problem is that one hundred grams of meat and the same amount of beans contain different amounts of BUN in percentage terms. At first, it is necessary to keep track of the amino acid content in the food consumed, then this should become automatic.

How many amino acids should you consume per day?

In the modern world, absolutely all food products contain nutrients necessary for humans, so there is no need to worry: all 20 protein amino acids are safely supplied from food, and this amount is enough for a person who leads a normal lifestyle and at least slightly monitors his diet.

An athlete’s diet must be saturated with proteins, because without them it is simply impossible to build muscle mass. Physical exercise leads to a colossal consumption of amino acid reserves, so professional bodybuilders are forced to take special supplements. With intensive building of muscle relief, the amount of protein can reach up to one hundred grams of protein per day, but such a diet is not suitable for daily consumption. Any food supplement implies instructions containing different AMKs in doses, which must be read before using the drug.

The influence of peptides on the quality of life of an ordinary person

The need for proteins is present not only among athletes. For example, the proteins elastin, keratin, and collagen affect the appearance of hair, skin, nails, as well as the flexibility and mobility of joints. A number of amino acids affect the body, maintaining fat balance at an optimal level, providing sufficient energy for everyday life. After all, in the process of life, even with the most passive lifestyle, energy is expended, at least for breathing. In addition, cognitive activity is also impossible when there is a lack of certain peptides; maintaining the psycho-emotional state is carried out, among other things, by AMK.

Amino acids and sports

The diet of professional athletes involves a perfectly balanced diet that helps maintain muscle tone. Designed specifically for those athletes who are working on gaining muscle mass, they make life much easier.

As previously written, amino acids are the main building blocks of proteins necessary for muscle growth. They are also able to speed up metabolism and burn fat, which is also important for beautiful muscle definition. When training hard, it is necessary to increase your BUN intake due to the fact that they increase the rate of muscle building and reduce post-workout pain.

The 20 amino acids in proteins can be consumed both as part of aminocarbon complexes and from food. If you choose a balanced diet, then you need to take into account absolutely all grams, which is difficult to implement when the day is very busy.

What happens to the human body when there is a lack or excess of amino acids

The main symptoms of amino acid deficiency are: poor health, lack of appetite, brittle nails, increased fatigue. Even with a lack of BUN alone, a huge number of unpleasant side effects occur, which significantly impair well-being and productivity.

Oversaturation with amino acids can lead to disruptions in the functioning of the cardiovascular and nervous systems, which, in turn, is no less dangerous. In turn, symptoms similar to food poisoning may appear, which also does not entail anything pleasant.

In everything you need to know when to stop, so maintaining a healthy lifestyle should not lead to an excess of certain “useful” substances in the body. As the classic wrote, “the best is the enemy of the good.”

In the article we looked at the formulas and names of all 20 amino acids; the table of the content of the main AMAs in products is given above.

1. How many nucleotides of adenine, thymine, guanine and cytosine are contained in a fragment of a DNA molecule, if 450 nucleotides with thymine are found in it, which is 30% of the total number of nucleotides in this DNA fragment?
1. % of other nucleotides known. A=T=30. G+C=100-(30+30)=20%.
Quantity A 450 nucleotides. Let's add up the proportion. 450-30%; x-20%. Acuity G and C 300 nucleotides cutaneous
2. The molecular weight of a polypeptide is 70,000. Determine the length of the gene encoding it if the molecular weight of one amino acid is on average 100, and the distance between adjacent nucleotides in the DNA chain is 0.34 nm.
Amino acid strength=70000:100=700
Number of nucleotides 3*700=2100, gene density 2100*0.34=714 nm
3. The rate of elongation of the RNA molecule is 50 nucleotides per second. How much time must be spent on the synthesis of RNA containing information about the structure of a protein whose molecular weight is 4500, if the average molecular weight of one amino acid is 100.
4500:100=45 amino acids; RNA has 45*3=135 nucleotides, speed 2.35 s
4. All types of RNA are synthesized on a DNA matrix. The fragment of the DNA molecule on which the central loop region is synthesized has the following nucleotide sequence: - ATAGCTGAACGGATCT-. Establish the nucleotide sequence of the region of the tRNA molecule that is synthesized on this DNA fragment, and the amino acid that this tRNA will carry during protein biosynthesis if the third triplet corresponds to the tRNA anticodon. Explain your answer.
The third triplet corresponds to the anticodon, only T is changed to U. It looks like a GAA triplet, the amino acid is found in the table.
5. How many turns does the section of the DNA double helix have that controls the synthesis of a protein with a molecular weight of 30,000, if the molecular weight of one amino acid is on average 100, and there are 10 nucleotides per turn of the DNA helix.
Amino acids in protein are 30000:100=300. The number of nucleotides in the gene that codes for this protein is 300*3=900. Spiral turns 90.
6. The segment of the DNA molecule that determines the primary structure of the protein contains the following sequence of nucleotides: - ATG GCT CTC CAT TGG - . Determine the nucleotide sequence of mRNA, the number of tRNAs that are involved in protein biosynthesis, and the nucleotide composition of tRNA anticodons. Explain your results.
UAC CGA GAG GUA ACC, t-RNA 5; antikodoni AUG GCU TsUTs TsAU UGG
7. Information part and - RNA contains 135 nucleotides. Determine the number of amino acids included in the protein it encodes, the number of tRNA molecules involved in the biosynthesis of this protein, the number of triplets in the gene section encoding the primary structure of this protein (it should be taken into account that one tRNA delivers one amino acid to the ribosome). Explain your results.
45 amino acids, triplets and tRNAs.
8. Sequence of nucleotides in a DNA chain:
- TSTTATTSATTSGAAG -. Explain the consequences of accidentally adding a guanine nucleotide between the fourth and fifth nucleotides.
TsTA TsGT TAT TsATs GAA G the structure of the protein will change. iRNA GAU GCA AUA GUG TSUU
9. The polypeptide consists of 27 amino acids. Determine the number of nucleotides in the gene section that encodes the primary structure of this polypeptide, the number of codons on the mRNA corresponding to these amino acids, the number of tRNA molecules involved in the biosynthesis of this polypeptide. Explain your answer.
81 nucleotides, 27 iRNA codons, 27 tRNA
10. All types of RNA are synthesized on a DNA matrix. The fragment of the DNA molecule on which the region of the central loop of t-RNA is synthesized has the following nucleotide sequence: - TAT CGA CTT GCCTGA-. Establish the nucleotide sequence of the region of the tRNA molecule that is synthesized on this DNA fragment, and the amino acid that this tRNA will carry during protein biosynthesis if the third triplet corresponds to the tRNA anticodon. Explain your answer.
anticodon will be CUU
11. The two chains are held against each other by hydrogen bonds. Determine: the number of double and triple hydrogen bonds in this DNA chain, as well as its length, if it is known that there are 12 nucleotides with adenine and 20 with guanine in both chains.

12*2*+20*3
12. A section of one of the two chains of a DNA molecule contains 200 nucleotides with adenine, 300 nucleotides with thymine, 250 with guanine and 120 with cytosine. What number of nucleotides with A, T, G, C are contained in a DNA molecule (in two chains)? How many amino acids should a protein encoded by this part of the DNA molecule contain? Please clarify the answer.

T=200=A, A=300=T, C=250=G, G=120=C. Nucleotides in two lances 870*2, in the same gene 870, amino acids 290
13. The two chains are held against each other by hydrogen bonds. Determine the number of hydrogen bonds in this DNA chain, if you know that there are 42 nucleotides with adenine and 32 with guanine in both chains.
like task 11
14. A section of a DNA molecule has the structure: ACC ATA GCT CAA GGA GGC TTA. Determine: the structure of the second strand of DNA, the nucleotide composition of RNA and the number of triple hydrogen bonds in this section of the DNA molecule.
Number of aqueous compounds between adenine and thymine 2, between guanine and cytosine 3
DNA TGG TAT CGA GTT CCT CCG AAT
15. Two chains are held against each other by hydrogen bonds. Determine the number of nucleotides with A, T, G, C in a DNA molecule in which 42 nucleotides are connected to each other by two hydrogen bonds and 48 nucleotides by three hydrogen bonds. Explain your results.

Two water days combine A and T, so they are 21 each, and G and C are 24 each (48:2)
16. T-RNA with anticodons AAU, CCG, GCH, UAA, GCA participated in the biosynthesis of the polypeptide. Determine the nucleotide sequence of the section of each chain of the DNA molecule that carries information about the protein being synthesized, and the number of nucleotides containing A, G, T, C in a double-stranded DNA molecule. Explain your answer.
Anticodonies represent DNA. Coding lance AAT, TsTG, GCH, TAA, GCA. The substitute lancet, the one that is not copied during transcription, is attributed complementarily to TTA GGC CGC ATT CGT divergent nucleotides.
17. Protein consists of 210 amino acids. Determine how many times the molecular weight of the gene region encoding a given protein exceeds the molecular weight of the protein if the average weight of an amino acid is 110, and that of a nucleotide is 300. Explain your answer.
3*300*210:210*110
18. A fragment of a DNA chain has the nucleotide sequence: TTT AGC TGT CGG AAG. As a result of the mutation that occurred in the fifth triplet, the third nucleotide was replaced by A. Determine the sequence of nucleotides in and - RNA from the original fragment of the DNA chain and the changed one. Explain what will happen to a fragment of a protein molecule and its properties after a DNA mutation occurs.
AAA gene UUU codon, the primary structure of the protein and its power will change.

Although tasks C5 and C6 include the most
difficult to understand areas of biology
knowledge, almost all of them are compiled quite
specifically. They can be answered more often
just unambiguously, that is, just like
conceived by the authors themselves.
This completely excludes any
subjectivist interpretations when assessing knowledge
by the reviewing experts.

Before you start solving problems,
necessary:
have a very clear idea
about biological matrices: principles
copying and creating DNA molecules in the cell,
different types of RNA and proteins;
To do this you need to have a good understanding of
structure of large aperiodic molecules
nucleic acids and proteins (irregular
cell biopolymers);
It’s good to know what the genetic code is and
its properties.

Genetic code (mRNA) table

Pay attention! When we talk about the genetic code, we really mean the sequence of nucleotides (triplets) of the D molecule

Pay attention!
When we talk about the genetic code, we
we really mean
nucleotide sequence
(triplets) DNA molecule.
The genetic decoding table
code presented in
exam task C5 for
problem solving, compiled for
triplets (codons)
mRNA, not DNA triplets!

The theoretical material in this section is very large, but let’s highlight the main thing:

DNA is found in the nucleus and is made up of two
complementary chains, in it
information about
sequence of amino acids in a protein;
During transcription on one of the circuits
DNA is synthesized and RNA enters
into the cytoplasm and serves as a matrix for
protein synthesis;
Structural unit of nucleic acid
acids (NA) is a nucleotide, their
There are five types - adenyl (A),
thymidyl (T), guanyl (G),
cytidyl (C), uridyl (U)
Each type of NC contains only four
type of nucleotide, in DNA - A, T, G, C; in RNA –
A, U, G, C;

One amino acid is encoded by three
adjacent nucleotides
-TRIPLET (codon);
One amino acid is transported to
site of synthesis of one t-RNA, at the top
which the anticodon is located;
Nucleotides combine according to the principle
complementarity: opposite A
T is located, and opposite G-C.
This is the minimum information required
to solve problems.

Let's learn to decide!
Given a section of the right DNA strand:
A AGAGTGCGTTTTCAG
Using the genetic code table, we will construct
fragment of a protein encrypted at this site
DNA
DNA
I-RNA
protein
A AGAGTGCGTTTTCAG
UUTTSATsGTSAAAGUTS
hair dryer
gray
arg
Liz
shaft

Problem 1

nucleotides:
GTTATGGAAGAAA.
Determine the nucleotide sequence on
mRNA, anticodons of the corresponding tRNA and
sequence of amino acids in the fragment

code.
Response elements:
1. Sequence of nucleotides on i-RNA:
TSAAUATZUUTZUU
2. Anticodons of t-RNA molecules: GUU, AUG, GAA, GAA
3. The sequence of amino acids in the molecule
squirrel:
gln-tir-lay-ley

10.

Problem 2
The translation process involved 30 tRNA molecules. Determine the number of amino acids included in
composition of the synthesized protein, as well as the number
triplets and nucleotides in the gene that encodes
this protein.

1. one tRNA transports one amino acid,
therefore, 30 tRNAs correspond to 30
amino acids, and protein consists of 30 amino acids;
2. one amino acid is encoded by a triplet of nucleotides,
This means that 30 amino acids encode 30 triplets;
3. number of nucleotides in the gene encoding the protein
of 30 amino acids - 30 x 3 = 90.

11.

Problem 3
A fragment of a DNA strand has the sequence
nucleotides:
GTGTATGGAAGT.
Define
subsequence
nucleotides
on
i-RNA,
anticodons
relevant
tRNA
And
subsequence
amino acids
V
fragment
protein molecules using genetics worksheet
code.
Response elements:
1. sequence of nucleotides on i-RNA:
TSATSAUATZUUTSA;
1. anticodons of tRNA molecules: GUG, UAU, GGA, AGU,
2. sequence of amino acids in a molecule
squirrel:
gis-ile-pro-ser

12.

Problem 4
Under the influence of nitrous acid, cytosine
turns into guanine. How the structure will change
tobacco mosaic virus protein, if the virus RNA
UTSGGGUUCTSAUUATSU,
coding
his
protein,
exposed to nitrous acid? At
use the genetic table to solve the problem
code.
Response elements:
1. original amino acid sequence
ser-gli-ser-ile-tre
2. altered RNA: UGGGGGUUGGAUUAGU
3. new amino acid sequence
tri-gli-tri-ile-ser;

13.

Problem 5
The polypeptide consists of 20 amino acids. Define
number of nucleotides in a gene region that
encodes the primary structure of this polypeptide,
number of codons per mRNA corresponding to these
amino acids, and the number of tRNA molecules involved
in the biosynthesis of this polypeptide.
The problem solution scheme includes:
1) the DNA genetic code is triplet, therefore the DNA gene section
encoding a polypeptide of 20 amino acids, contains 20 x 3 =
60 nucleotides;
2) the information part of the mRNA contains 20 codons;
3) for the biosynthesis of this polypeptide you will need 20 molecules
tRNA.

14.

Problem 6
All types of RNA are synthesized on a DNA template. Molecule fragment
DNA on which the region of the central loop of tRNA is synthesized,
has the following nucleotide sequence:
TCAGTCTGTTTCGAATG.
Determine the nucleotide sequence of the tRNA region,
which is synthesized on this fragment and amino acid,
which this t-RNA will carry during protein biosynthesis,
if the third triplet corresponds to the tRNA anticodon. Answer
explain. To solve the problem, use the genetic table
code.
Response elements:
1. Nucleotide sequence of the mRNA region
AGUTSGTSGAAGTSUUATS;
2. Nucleotide sequence of the GAA anticodon (third
triplet) corresponds to the codon on the mRNA TSUU;
3. It corresponds to the amino acid GLU, which will be transferred
this tRNA.

15.

Problem 7
A section of a DNA molecule has the following structure
TSTAGGATTGTATSAT.
Determine the nucleotide sequence
corresponding region of m-RNA, sequence
amino acids in a polypeptide synthesized by mRNA.
How will the amino acid sequence change in
polypeptide, if as a result of mutation from
of the DNA region encoding it, the 5th, 12th, 15th will fall out
nucleotides? Use the table to solve the problem
genetic code.
Response elements:
1. m-RNA: GAUZZUGATSAUAGUA;
2. Polypeptide before mutation:
Asp-pro-asp-ile-val;
3. Polypeptide after mutation: asp-leu-tre-cis.

16.

Problem 8
The molecular weight of the polypeptide is 55,000.
Determine the length of the gene encoding it if
average molecular weight of one amino acid
equals 100, and the distance between adjacent nucleotides
in a DNA chain is 0.34 nm.
Response elements:
1. The number of amino acids in the polypeptide is -55000/100=550;
2. Number of nucleotides of the coding region of DNA
(gene) – 550*3=1650;
3. length of the coding region of DNA (gene) –
1650*0.34=561 nm

17.

Problem 9
How many nucleotides adenine (A), thymine are contained in
(T), guanine (G) and cytosine (C) in the fragment
DNA molecules, if 180 are found in it
cytosine(C) nucleotides, which is 20% of
total number of nucleotides in this fragment
DNA?
Response elements:
1. Adenine (A) is complementary to thymine (T), and guanine (G) is
cytosine(C), therefore the number of complementary
nucleotides are the same;
2. Cytosine (C) contains 20%, which means guanine (G)
also 20%, adenine (A) and thymine (T) 100% - (20% + 20%) = 60%: 2 = 30%;
3. Cytosine (C) contains 180 nucleotides, which means
guanine (G) is also 180, adenine (A) and thymine (T) -
180/20*30=270 nucleotides

18.

Problem 10
Protein consists of 200 amino acids. Install in
how many times the molecular weight of the gene region,
encoding this protein exceeds
molecular weight of the protein, if average
The molecular weight of an amino acid is 110, and that of a nucleotide is 300.
Response elements:
1. The genetic code is triplet, therefore protein,
consisting of 200 amino acids, encodes 600
nucleotides.
2. Protein molecular weight 200*110=22,000;
molecular weight of the gene is 300*600=180,000.
3. A section of DNA is heavier than the protein it encodes,
approximately 8.1 times (180,000:22,000)

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

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) in which information about one protein is encoded is called gene.

Transcription- This is the rewriting of information from DNA to mRNA (information 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 the mRNA codons according to the principle of complementarity. The ribosome connects the amino acids brought by tRNA with a peptide bond to form a protein.

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

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

Genecode properties

1) Triplety: 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 Unified State Exam there may also 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

Problems on the number of nucleotides/amino acids
3 nucleotides = 1 triplet = 1 amino acid = 1 tRNA

Tasks at ATGC
DNA mRNA tRNA
A U A
T A U
G C G
Ts G Ts

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

Answer

Choose one, the most correct option. The primary structure of a protein molecule, specified by the nucleotide sequence of mRNA, 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 path of implementation 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. Select the correct sequence of information transfer during 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 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. The anticodon AAU on transfer RNA corresponds to a triplet on DNA
1) TTA
2) AAT
3) AAA
4) TTT

Answer

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

Answer

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

Answer

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

Answer

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

Answer

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

Answer

4. Establish the sequence of stages of 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) lengthening of the polypeptide chain
5) release of mRNA from the nucleus into the cytoplasm

Answer

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

Answer

Choose one, the most correct option. Which transfer RNA anticodon corresponds to the TGA triplet in the DNA molecule
1) ACU
2) TsUG
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 triple 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 encode one amino acid

Answer

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

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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 matrix
3) proteins are synthesized on the mRNA matrix in the ribosome
4) hydrogen bonds between DNA molecules are broken

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

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

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All but two of the following features can be used to describe the functions of nucleic acids in a cell. Identify two characteristics that “drop out” from the general list and write down the numbers under which they are indicated in the table.
1) carry out homeostasis
2) transfer hereditary information from the nucleus to the ribosome
3) participate in protein biosynthesis
4) are part of the cell membrane
5) transport amino acids

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

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

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

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

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

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

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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 corresponding number in your answer.

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

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

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5. How many nucleotides in a gene section encode a protein fragment of 25 amino acid residues? In your answer, write down only the corresponding number.

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

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AMINO ACIDS - tRNA
1. What number of tRNAs took part in the synthesis of a protein that includes 130 amino acids? Write the corresponding number in your answer.

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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 corresponding number in your answer.

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

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4. Protein consists of 220 amino acid units (residues). Determine the number of tRNA molecules required to transport amino acids to the site of protein synthesis. Write down only the corresponding number in your answer.

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

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2. How many triplets code for 32 amino acids? In your answer, write down only the corresponding number.

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

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2. How many amino acids does 900 nucleotides code for? In your answer, write down only the corresponding number.

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3. What is the number of amino acids in a protein if its coding gene consists of 600 nucleotides? In your answer, write down only the corresponding number.

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4. How many amino acids does 1203 nucleotides code for? In your answer, write down only the number of amino acids.

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

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

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NUCLEOTIDES - tRNA
What number of transport RNA molecules were involved in translation if the gene region contains 930 nucleotide residues?

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

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

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JUST
How many nucleotides make up one mRNA codon?

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How many nucleotides make up one stop codon of mRNA?

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How many nucleotides make up the tRNA anticodon?

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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. Write down only the corresponding number in your answer.

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There are 3000 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 DNA strand. In your answer, write down only the number corresponding to the number of amino acids.

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Nine tRNA molecules were involved in the process of translation of the oxytocin hormone molecule. 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 the numbers in the order specified in the task, without separators (spaces, commas, etc.).

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

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

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In which of the listed cell organelles do matrix synthesis reactions occur? 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

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Look at the picture depicting the processes occurring in a 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 of chemical reactions. For each letter, select the corresponding term from the list provided.
1) replication
2) transcription
3) broadcast
4) denaturation
5) exothermic reactions
6) substitution reactions
7) matrix synthesis reactions
8) splitting reactions

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

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1. Establish a correspondence between the processes and stages of protein synthesis: 1) transcription, 2) translation. Write numbers 1 and 2 in the correct order.
A) transfer of amino acids by tRNA
B) DNA is involved
B) synthesis of mRNA
D) formation of a polypeptide chain
D) occurs on the ribosome

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2. Establish a correspondence between the characteristics and processes: 1) transcription, 2) translation. Write 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 monomers
D) in eukaryotes occurs in the nucleus
D) DNA is used as a matrix
E) carried out by the enzyme RNA polymerase

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

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All of the signs listed below, except two, are used to describe the process shown in the figure. Identify two characteristics that “drop 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 the nucleotide sequence of molecules of various types of RNA
2) the process of converting 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 occurs in ribosomes
5) the result of the process is RNA synthesis

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The molecular weight of the polypeptide is 30,000 c.u. 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 corresponding number in your answer.

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

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

Answer

All of the following characteristics, except two, can be used to describe the process of protein biosynthesis in a cell. Identify two characteristics that “drop out” from the general list, and write down the numbers under which they are indicated in your answer.
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 to form molecules.
5) The assembly of protein molecules is carried out in lysosomes.

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Find three errors in the given text. Indicate the numbers of the proposals in which they are made.(1) During protein biosynthesis, matrix synthesis reactions occur. (2) Template synthesis reactions include only replication and transcription reactions. (3) As a result of transcription, mRNA is synthesized, the template for which is the entire DNA molecule. (4) After passing through the pores of the nucleus, the mRNA enters the cytoplasm. (5) Messenger RNA is involved in tRNA synthesis. (6) Transfer RNA delivers amino acids for protein assembly. (7) The energy of ATP molecules is spent on the connection of each amino acid with tRNA.

Answer

All but two of the following concepts are used to describe translation. Identify two characteristics that “drop 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

All of the characteristics listed below, except two, are used to describe the processes necessary for the synthesis of a polypeptide chain. Identify two characteristics that “drop 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) formation of pyruvic acid
5) connection of amino acids

Answer

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