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 GUU triplet, then in a dog this amino acid can be encoded by triplets (see table):
1) GUA and GUG 3) CUC and CUA
2) UTC and UCA 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?
1) TCG 2) UUG 3) TTC 4) CCG
In the body's metabolism the leading role belongs to proteins and nucleic acids.
Protein substances form the basis of all vital important structures cells have an unusually high reactivity, 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 specific 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 starts up 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.
In this way, genetic code - a unified system for recording hereditary information in nucleic acid molecules in the form of a sequence of nucleotides. Genetic code founded 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. Means, smallest number nucleotides encoding one amino acid is equal to 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 (triplets), and, starting at a certain codon, 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 the systematic position of 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.
Thereafter 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 is accurate transmission 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 a new half of it is synthesized on each old half of the molecule.
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 |
In this way, 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.
In this way,
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 that 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 largest scientific achievement XX 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?
1-V A R I A N T
Part A
1. The material carrier of hereditary information in a cell is:
a) mRNA b) tRNA c) DNA d) chromosomes
2. Cell DNA carries information about the structure:
a) proteins, fats, carbohydrates c) proteins and fats
b) amino acids d) proteins
3. Which of the nucleotides is not part of DNA?
a) thymine; b) uracil; c) guanine; d) cytosine; e) adenine.
4. How many new single strands are synthesized by doubling one molecule?
a) four; b) two; c) one; d) three
5. Which of the facts confirms that DNA is the genetic material of the cell?
a) the amount of DNA in all cells of the body is constant
b) DNA is made up of nucleotides
c) DNA is located in the nucleus of the cell
d) DNA is a double helix
6. If the nucleotide composition of DNA is ATA-GCH-TAT-, then what should be the nucleotide composition of mRNA?
a) -TAA-CHC-UUA- c) -UAU-CHC-AUA-
b) –TAA-GCG-UTU- d) –UAA-CGTs-ATA-
7. Synthesis of mRNA begins:
a) from the separation of the DNA molecule into two strands
b) with doubling each thread
c) with the interaction of RNA polymerase and gene
d) splitting the gene into nucleotides
8. Where is mRNA synthesized?
a) in ribosomes c) in the nucleolus
b) in the cytoplasm d) in the nucleus
9. The amino acid glutamine is encoded by the codon GAA. Which DNA triplet carries information about this amino acid?
a) GTT b) CAA c) TSUU d) CTT
10. What information does one DNA triplet contain?
a) information about the sequence of amino acids in a protein
b) information about one feature of the organism
c) information about one amino acid included in the protein chain
d) information about the beginning of the beginning of mRNA synthesis
11. Which of the following triplets can stop the synthesis of the polypeptide chain?
a) GAU b) AAG c) UAA d) ASU
12. Broadcast is:
a) synthesis of a polypeptide chain on ribosomes
b) tRNA synthesis
c) mRNA synthesis according to the DNA template
d) rRNA synthesis
13. The amount of tRNA is:
a) the number of all DNA codons
b) the number of mRNA codons encoding amino acids
c) the number of genes
d) the amount of proteins in the cell
14. Protein synthesis is completed at the moment:
a) the appearance of a "punctuation mark" on the ribosome
b) depletion of enzyme reserves
c) codon recognition of the anticodon
d) amino acid attachment to tRNA
15. Which of the following reactions involve enzymes?
a) in the synthesis of mRNA
b) in the interaction of tRNA with an amino acid
c) in the assembly of a protein molecule
d) in all the indicated reactions
16. It is known that the cells of a multicellular organism have the same genetic information, but contain different proteins. Which of the hypotheses explaining this fact is the most correct?
a) the diversity of proteins does not depend on the characteristics of the cell
b) in each cell type, only a part of the organism's genetic information is realized
c) the presence of proteins in a cell does not depend on genetic information
17. The code unit of the genetic code is:
a) nucleotide c) triplet
b) amino acid d) tRNA
18. In the nucleus, information about the sequence of amino acids in a protein molecule is copied from the DNA molecule to the molecule:
A) glucose; b) tRNA; c) mRNA; d) ATP
19. Transfer RNA is
a) amino acid c) lipid
b) glucose d) nucleic acid
20. If tRNA anticodons consist only of AUA triplets, then from what amino acid will the protein be synthesized?
a) from cysteine c) from tyrosine
b) from tryptophan d) from phenylalanine
21. How many nucleotides are in a gene encoding a sequence of 60 amino acids in a protein molecule?
A) 60 b) 120 c) 180 d) 240
Part B.
IN 1.
What are the features of protein biosynthesis reactions in a cell?
a) the reactions are matrix in nature: protein is synthesized on mRNA
b) reactions occur with the release of energy
c) reactions are accelerated by enzymes
e) protein synthesis occurs on the inner membrane of mitochondria
IN 2. Define terms
1. Reactions of matrix synthesis - ………
2. Gene - ………………
3. Intron - ………………….
4. Processing - ……………..
5. RNA polymerase -……………….
6. The code is collinear - ……………..
7. The code is not covered - …………………
8. The code is unambiguous - ……………..
Part C . Give a detailed answer.
C1. transcription mechanism.
C2. Regulation of protein biosynthesis in prokaryotes on the example of E.coli lactose operon
C3. Solve problems:
№1 . The protein molecule consists of the following amino acids: -arginine-lysine-alanine-proline-leucine-valine-. How will the protein structure change if guanine (all) is replaced by cytosine in the coding gene.
№2 . Protein consists of 245 amino acids. Determine the length of the gene encoding this polypeptide and calculate what will be harder and by how many times: a protein or a gene?
Test Biosynthesis of proteins. Regulation of biosynthesis"
OPTION 2
Part A Choose one correct answer.
1. The basis of the individuality, specificity of organisms is:
a) the structure of body proteins c) the structure of cells
b) cell functions d) structure of amino acids
2. Information is encoded in one gene:
a) about the structure of several proteins
b) about the structure of one of the DNA chains
c) about the primary structure of one protein molecule
d) about the structure of the amino acid
3. What bonds are broken in the DNA molecule when it is doubled?
a) peptide
b) covalent, between carbohydrate and phosphate
c) hydrogen between two strands of the molecule
d) ionic
4. Which of the DNA duplication schemes is correct?
a) a DNA molecule, when duplicated, forms a completely new daughter molecule
b) a daughter DNA molecule consists of one old and one new strand
c) maternal DNA breaks down into small fragments
5. Which of the named human cells does not have DNA?
a) mature leukocyte c) lymphocyte
b) mature erythrocyte d) neuron
6. Transcription is called:
a) the process of mRNA formation
b) the process of DNA duplication
c) the process of formation of a protein chain on ribosomes
d) the process of combining tRNA with amino acids
7. The amino acid tryptophan is encoded by the codon UGG. Which DNA triplet carries information about this amino acid?
A) ACC b) TCC c) UCC d) ATG
8. Where is rRNA synthesized?
a) in ribosomes c) in the nucleolus
b) in the cytoplasm d) in the nucleus
9. What will the mRNA chain section look like if the second nucleotide of the first triplet in DNA (-GCT-AGT-CCA-) is replaced by the T nucleotide?
a) -CGA-UCA-GGT- c) -GUU-AGU-CCA-
b) – CAA-UCA-GSU- d) –CCU-UTCU-GSU-
10. Which of the enzymes carries out the synthesis of mRNA?
a) RNA synthetase
b) RNA polymerase
c) DNA polymerase
11. The DNA code is degenerate because:
a) one amino acid is encoded by one codon
b) several amino acids are encrypted by one codon
c) between the codons of one gene there are "punctuation marks"
d) one amino acid is encrypted by several codons
12. tRNA anticodons are complementary:
a) rRNA codons c) mRNA codons
b) DNA codons d) all specified codons
13. The second stage of protein synthesis is:
a) in the recognition and attachment of amino acids to tRNA
b) in rewriting information from DNA
c) in the separation of amino acids from tRNA on the ribosome
d) in the association of amino acids into a protein chain
14. Synthesized on the polysome:
a) one protein molecule
b) several molecules of various proteins
c) several molecules of identical proteins
d) all options are possible
15. Attachment of an amino acid to tRNA goes:
a) with the release of energy
b) with energy absorption
c) not accompanied by an energy effect
16. Which of the following reactions corresponds to the stage of translation elongation:
a) removing information from DNA
b) tRNA anticodon recognition of its codon on mRNA
c) amino acid cleavage from tRNA
d) delivery of mRNA to ribosomes
e) attachment of an amino acid to a protein chain with the help of an enzyme
17. The uniqueness of the genetic code is manifested in the fact that each triplet encodes:
a) several amino acids
b) no more than two amino acids
c) three amino acids
d) one amino acid
18. Correspondence of a tRNA triplet to a triplet in mRNA underlies:
a) interactions of tRNA with amino acids
b) movement of the ribosome along the mRNA
c) movement of tRNA in the cytoplasm
d) determining the place of an amino acid in a protein molecule
19. "Punctuation marks" between genes are codons (triplets):
a) do not code for amino acids
b) at which transcription ends
c) at which transcription begins
d) where the broadcast starts
20. Which tRNA triplet is complementary to an mRNA codon?
a) CCT; b) AGC; c) HCT; d) CGA
21. DNA molecules are the material basis of heredity, as they encode information about the structure of molecules:
a) polysaccharides c) proteins
b) lipids d) amino acids
Part B.
IN 1. Choose three correct answers
What is the relationship between protein biosynthesis and oxidation organic matter?
a) in the process of oxidation of organic substances, energy is released, which is consumed during protein biosynthesis
b) in the process of biosynthesis, organic substances are formed, which are used at the entrance of oxidation
c) energy is used in the process of photosynthesis sunlight
d) water enters the cell through the plasma membrane
e) in the process of biosynthesis, enzymes are formed that accelerate oxidation reactions
f) protein biosynthesis reactions occur in ribosomes with the release of energy
IN 2. Define terms
1.Replication - ………
2. Genetic code - …………………
3. Exon -…………….
4. Splicing - ……………….
5. Helicase (Helicase) -…………………
6. The code is degenerate -………….
7. The code is universal - ……………
8. Stop codons (Synthesis terminators) -
Part C . Give a detailed answer.
C1. translation mechanism.
C2. Differences in protein biosynthesis in prokaryotes and eukaryotes
C3. Solve problems:
№1 . How will the substitution of the third nucleotide in the second triplet for cytosine affect the structure of the synthesized protein, if the original DNA had the following form: CGAACAAGGGCATCH.
№2 . Molecular mass DNA is 248400, the share of guanyl nucleotides is 24840. Determine the content of each type of nucleotide in this DNA (including in%), the length of DNA, the number of amino acids in the synthesized protein, and the mass of the protein. Calculate which is heavier and by how many times: a gene or a protein?
protein biosynthesis.1. The structure of one protein is determined by:
1) a group of genes 2) one gene
3) one DNA molecule 4) a set of genes of an organism
2. The gene encodes information about the sequence of monomers in the molecule:
1) tRNA 2) AA 3) glycogen 4) DNA
3. Triplets are called anticodons:
1) DNA 2) t-RNA 3) i-RNA 4) r-RNA
4. Plastic exchange consists mainly of reactions:
1) decay of organic substances 2) decay of inorganic substances
3) synthesis of organic substances 4) synthesis of inorganic substances
5. Protein synthesis in a prokaryotic cell occurs:
1) on ribosomes in the nucleus 2) on ribosomes in the cytoplasm 3) in the cell wall
4) on the outer surface of the cytoplasmic membrane
6. The translation process takes place:
1) in the cytoplasm 2) in the nucleus 3) in mitochondria
4) on the membranes of the rough endoplasmic reticulum
7. Synthesis occurs on the membranes of the granular endoplasmic reticulum:
1) ATP; 2) carbohydrates; 3) lipids; 4) proteins.
8. One triplet encodes:
1. one AK 2 one sign of an organism 3. several AKs
9. Protein synthesis is completed at the moment
1. recognition of a codon by an anticodon 2. appearance of a “punctuation mark” on the ribosome
3. i-RNA entry to the ribosome
10. The process, as a result of which information is read from the DNA molecule.
1. translation 2. transcription 3. transformation
11. The properties of proteins are determined ...
1.secondary protein structure 2.protein primary structure
3.The tertiary structure of the protein
12. The process by which an anticodon recognizes a codon on mRNA
13. Stages of protein biosynthesis.
1. transcription, translation 2. transformation, translation
14. The t-RNA anticodon consists of UCG nucleotides. Which DNA triplet is complementary to it?
1.UUG 2. TTC 3. TCG
15. The number of t-RNAs involved in translation is equal to the number of:
1. i-RNA codons encoding amino acids 2. i-RNA molecules
3 Genes included in the DNA molecule 4. Proteins synthesized on ribosomes
16. Establish the sequence of nucleotides of i-RNA during transcription from one of the DNA chains: A-G-T-C-G
1) U 2) G 3) C 4) A 5) C
17. During the replication of a DNA molecule, the following is formed:
1) a thread that has broken up into separate fragments of daughter molecules
4) in some cases, one of the chains of the DNA molecule, in others, the entire DNA molecule.
19. The process of self-doubling of the DNA molecule.
1.replication 2.repair
3. reincarnation
20. During protein biosynthesis in a cell, ATP energy:
1) consumed 2) stored
3) is not consumed and is not allocated
21. In somatic cells of a multicellular organism:
1) a different set of genes and proteins 2) the same set of genes and proteins
3) the same set of genes, but a different set of proteins
4) the same set of proteins, but a different set of genes
22.. One DNA triplet carries information about:
1) amino acid sequences in a protein molecule
2) a sign of an organism 3) an amino acid in a synthesized protein molecule
4) the composition of the RNA molecule
23. Which of the processes does not occur in cells of any structure and function:
1) protein synthesis 2) metabolism 3) mitosis 4) meiosis
24. The term "transcription" refers to the process:
1) duplication of DNA 2) synthesis of i-RNA on DNA
3) the transition of i-RNA to ribosomes 4) the creation of protein molecules on the polysome
25. A section of a DNA molecule that carries information about one protein molecule is:
1) gene 2) phenotype 3) genome 4) genotype
26. Transcription in eukaryotes occurs in:
1) cytoplasm 2) endoplasmic membrane 3) lysosomes 4) nucleus
27. Protein synthesis occurs in:
1) granular endoplasmic reticulum
2) smooth endoplasmic reticulum 3) nucleus 4) lysosomes
28. One amino acid is encoded by:
1) four nucleotides 2) two nucleotides
3) one nucleotide 4) three nucleotides
29. The triplet of ATC nucleotides in the DNA molecule will correspond to the codon of the i-RNA molecule:
1) TAG 2) UAG 3) UTC 4) CAU
30. Punctuation marks of the genetic code:
1. encode certain proteins 2. trigger protein synthesis
31. The process of self-doubling of the DNA molecule.
1.replication 2.repair 3.reancornation
32. The function of i-RNA in the process of biosynthesis.
1. storage of hereditary information 2. transport of AA to ribosomes
3.feeding information to ribosomes
33. The process when tRNAs bring amino acids to ribosomes.
1.transcription 2.translation 3.transformation
34. Ribosomes synthesizing the same protein molecule.
1.chromosome 2.polysome 3.megachromosome
35. The process by which amino acids form a protein molecule.
1.transcription 2.translation 3.transformation
36. Matrix synthesis reactions include…
1. DNA replication 2. transcription, translation 3. both answers are correct
37. One DNA triplet carries information about:
1. Amino acid sequences in a protein molecule
2. Place a certain AK in the protein chain
3. Sign of a specific organism
4. Amino acid included in the protein chain
38. The gene encodes information about:
1) the structure of proteins, fats and carbohydrates 2) the primary structure of the protein
3) nucleotide sequences in DNA
4) amino acid sequences in 2 or more protein molecules
39. Synthesis of mRNA begins with:
1) DNA separation into two strands 2) interaction of the RNA polymerase enzyme and the gene
40. Transcription occurs:
1) in the nucleus 2) on the ribosomes 3) in the cytoplasm 4) on the channels of the smooth EPS
41. Protein synthesis does not occur on ribosomes in:
1) the causative agent of tuberculosis 2) bees 3) fly agaric 4) bacteriophage
42. During translation, the template for assembling the polypeptide chain of a protein is:
1) both strands of DNA 2) one of the strands of the DNA molecule
3) an mRNA molecule 4) in some cases, one of the DNA chains, in others, an mRNA molecule
energy for the reaction
E. Protein monomer
F Group of nucleotides encoding one amino acid
connections
2. DNA triplets
3. Ribosome
4. RNA polymerase
5. Amino acid
it is necessary to correlate the substances and structures involved in protein synthesis with their functions
1. What type of RNA carries hereditary information from DNA to the site of protein synthesis?2. What type of RNA carries amino acids to the site of protein synthesis?
3. what type of RNA carries hereditary information from the nucleus to the cytoplasm?
4. in which organisms the processes of transcription and translation are not separated in time and space?
5. How many mRNA nucleotides does the "functional center" of the ribosome include?
6. how many amino acids should be simultaneously in the large subunit of the ribosome?
7. how many genes can mRNA of prokaryotes include?
8. how many genes can eukaryotic mRNA include?
9.when the ribosome reaches the STOP codon, it attaches a molecule to the last amino acid
10. if there are many ribosomes on one mRNA at the same time, such a structure is called
11. for protein biosynthesis, as well as for other processes in the cell, energy is used
2. What are the names of the nuclear structures that store information about the body's proteins?
3. What molecule is a template (template) for mRNA synthesis?
4. What is the name of the process of synthesis of a polypeptide chain of a protein on a ribosome?
5. On what molecule is a triplet called a codon located?
6. On what molecule is a triplet called an anticodon located?
7. By what principle does an anticodon recognize a codon?
8. Where does the formation of the t-RNA + amino acid complex take place in the cell?
9. What is the name of the first stage of protein biosynthesis?
10. Given a polypeptide chain: -VAL - ARG - ASP- Determine the structure of the corresponding DNA chains.
lysosomes into mitochondria d cell center 4 all c-v and cells can be divided into 1 proteins and carbohydrates 2 carbohydrates and fats 3 fats and inorganic substances 4 inorganic and organic substances 5 the process of maturation of cell specialization is called 6 oxidation organic and ATP synthesis occurs in 7 the transfer of information from one nerve cell to another passes through 8 when the immune system is disrupted 1 protection from foreign bodies weakens 2 gas exchange 3 motor activity slows down 4 transport to -in is disturbed
