CH 15

Shine-Dalgarno

A 9-nucleotide sequence in prokaryotic mRNA that facilitates binding to the small ribosomal subunit is the ___________-___________ sequence.

Initiation

A complex forms between the ribosomal subunits, one mRNA molecule and the first tRNA molecule.

cytosol, mitochondria and chloroplasts.

A plant cell will have ribosomes in its mitochondria only. cytosol, mitochondria and chloroplasts. cytosol and chloroplasts only. chloroplasts only. cytosol only.

a messenger RNA transcript that has many bound ribosomes in the act of translation.

A polyribosome is a ribosome with three or more subunits. a messenger RNA transcript that has many bound ribosomes in the act of translation. many ribosomes bound to transfer RNAs. many messenger RNAs bound to the same two ribosomal subunits. a messenger RNA bound to a ribosome with three or more subunits.

c. a tRNA

A release factor is referred to as a "molecular mimic" because its structure is similar to a. a ribosome b. an mRNA c. a tRNA d. an elongation factor

stop codon.

A series of three nucleotide bases that signals the end of a polypeptide chain is a(n) stop codon. start codon. synonymous codon. antisense codon. sense codon.

sense codon

A series of three nucleotide bases that specifies the insertion of a particular amino acid into a polypeptide chain is a _____________ __________.

start codon.

A series of three nucleotide bases that specifies the placement of the amino acid methionine at the beginning of a polypeptide chain is a start codon. stop codon. nonsense codon. synonymous codon.

anticodon

A series of three nucleotides in transfer RNA that is complementary to a codon in messenger RNA is called a(n) ____________.

genetic code

A set of three-letter combinations of nucleotides called codons, each of which corresponds to a specific amino acid, represents the ___________ ___________.

aminoacyl-tRNA

A transfer RNA that has an amino acid attached to its 3' end is called a(n) _______-__________.

Third base of the codon

According to the wobble rules, which base of the codon can be mismatched with an anticodon base on the tRNA? Any of the three bases of the codon None of the three bases of the codon Third base of the codon Second base of the codon First base of the codon

elongation.

Amino acids are added sequentially to a growing polypeptide chain during elongation. termination. initiation.

Elongation

Amino acids are linked together in the order designated by the codons.

start

An AUG codon, which specifies the amino acid methionine and is often the first codon that begins a polypeptide sequence, is called a __________ codon.

a transfer RNA with an amino acid attached to its 3' end.

An aminoacyl-tRNA is a transfer RNA with an amino acid attached to its 5' end. a transfer RNA with an amino acid attached to its 3' end. a transfer RNA that is ready to pick up an amino acid. a transfer RNA that has delivered its amino acid to a growing peptide chain.

pyrrolysine. selenocysteine.

An exception to the genetic code involves the incorporation of which of the following chemically modified amino acids into polypeptides? pyrrolysine. acetylcysteine. methyl-arginine selenocysteine. methyl-lysine.

side chain

Another name for an amino acid's R group is ________ __________

enzyme

Archibald Garrod proposed that the buildup of homogentisic acid leading to the symptoms of alkaptonuria resulted from a missing ____________.

genetic code.

Arranging the four RNA nucleotides A, G, C and U in groups of three with all possible combinations leads to a set of codons called the ribosomal RNA sequence. genetic code. transfer RNA sequence. gene sequence. amino acid sequence.

release factor

At termination of translation, a stop codon is recognized by a(n) _____________ ______________.

A site on the ribosome.

At the beginning of each round of elongation during translation, binding of the tRNA carrying the next amino acid to be added to the polypeptide binds occurs at the E site on the ribosome. A site on the ribosome. P site on the ribosome. Shine-Dalgarno sequence.

People with insulin-resistance produce a lower level of the insulin receptors than people with proper insulin response.

Cells of human muscle and adipose tissue have a protein receptor for insulin embedded in their plasma membranes. The receptor is a product of the INSR gene, where the dominant allele leads to a functional version of the protein. When insulin binds to this receptor, a cascade of reactions occurs that leads to an increase in the number of glucose transporters present in the membranes. This allows the uptake of glucose from the bloodstream into muscle and adipose cells. Some cases of insulin-resistance, observed in patients with obesity, are related to slower rates of glucose uptake. Which is the best explanation for differences at the cellular level for insulin-resistance contrasted with proper insulin response? People with insulin-resistance produce a higher level of insulin receptors than people with proper insulin response. People with insulin-resistance produce the insulin receptor while people with proper insulin response are lacking the receptor. People with normal insulin response have an extra copy of the INSR gene that codes for the insulin receptor. People with insulin-resistance produce a lower level of the insulin receptors than people with proper insulin response. People with insulin-resistance are missing the INSR gene that codes for the insulin receptor.

the types of proteins produced within each cell.

Cells of the pancreas secrete the hormone insulin to assist with glucose uptake while neurons release neurotransmitters to conduct nerve signals. The difference in products released by these two types of cells depends on differences in DNA content between the two types of cells. differences in the structure of ribosomes found in each type of cell. the genetic code between the two types of cells. the types of proteins produced within each cell.

wobble

Codons UUC and UUU lead to the placement of phenylalanine at a specific position in the protein chain. This type of mismatch in codon-anticodon binding that can occur at the third base of the codon is called __________.

Polyribosomes, or polysomes, are transcripts with multiple ribosomes translating simultaneously.

Define polysome

anticodon; codon

During elongation, the ______ of the incoming tRNA binds to the ______ of the mRNA. codon; anticodon amino acid; codon anticodon; codon elongation factor; initiation factor codon; amino acid

d. all of the above events occur

During the initiation stage of translation in bacteria, which of the following events occur(s)? a. IF1 and IF3 bind to the 30S subunit b. the mRNA binds to the 30S subunit, and tRNA^(fMet) binds to the start codon in the mRNA c. IF2 hydrolyzes its GTP and is released; the 50S subunit binds to the 30S subunit d. all of the above events occur

c. P site, a peptide bond, A site

During the peptidyl transfer reaction, the polypeptide, which is attached to a tRNA in the __________ becomes bound via ________ to an amino acid attached to a tRNA in the ________ a. A site, several hydrogen bonds, P site b. A site, a peptide bond, P site c. P site, a peptide bond, A site d. P site, several hydrogen bonds, A site

Translation

During which process is the code of mRNA used to synthesize a polypeptide? Translation Replication Transcription

R group.

Each of the 20 amino acids has a unique amino group. R group. central carbon. carboxylic acid group.

In a prokaryotic cell, transcription and translation are coupled; that is, translation begins while the mRNA is still being synthesized. In a eukaryotic cell, transcription occurs in the nucleus, and translation occurs in the cytoplasm.

Explain what is meant by the coupling of transcription and translation. Does this coupling occur in bacterial and/or eukaryotic cells? Explain

the structures of release factors, which are proteins, resemble the structures of tRNAs

Explain why release factors are called "molecular mimics"

quaternary

For a protein, an association of two or more polypeptide chains represents its _____________ structure.

adaptor

Francis Crick proposed that certain types of RNA molecules were involved in the incorporation of amino acids into a polypeptide chain in the _____________ hypothesis.

protein-encoding

Genes that determine the amino acid sequence of a polypeptide are called _______-__________ genes, or structural genes.

protein-encoding genes.

Genes that determine the order of amino acids found in a polypeptide are called protein-encoding genes. ribosomal RNA genes. transfer RNA genes.

341

How many rounds of elongation are required to build a polypeptide with 342 amino acids? 341 342 113 343 171

prokaryotic

In ______ cells, the initiator tRNA is carrying the amino acid N-formylmethionine. eukaryotic prokaryotic

prokaryotic

In ______ cells, the initiator tRNA is carrying the amino acid N-formylmethionine. prokaryotic eukaryotic

cell-free translation of copolymers and triplet-binding assays.

In addition to cell-free translation experiments with mixtures of synthetic RNAs, efforts to decipher the genetic code included DNA-RNA binding assays and triplet-binding assays. cell-free translation of copolymers and triplet-binding assays. transcription assays and cell-free translation of copolymers. in vivo assays of specific amino acid and mRNA binding interactions

single enzyme

In experiments where Beadle and Tatum were able to deduce the steps in a biochemical pathway, they concluded that a single gene controlled the synthesis of a ______ ______. single gene single carbohydrate single enzyme single chromosome Second

single gene

In experiments where Beadle and Tatum were able to deduce the steps in a biochemical pathway, they concluded that the synthesis of a single enzyme was controlled by a ______ single chromosome single enzyme single gene Second

start codon

In prokaryotic cells, a transfer RNA carrying N-formylmethionine recognizes the ______ and is the first tRNA to bind to the ribosomal subunits, so it is called the initiator tRNA. exon promoter operon start codon stop codon

translation of an mRNA beginning before its transcription has been completed.

In prokaryotic cells, the coupling of transcription and translation refers to both transcription and translation occurring on the ribosome. both transcription and translation occurring in the nucleus. transcription of an mRNA occurring before its translation has been completed. translation of an mRNA beginning before its transcription has been completed.

coupling

In prokaryotic cells, translation of an mRNA begins before its transcription has been completed. This phenomenon is called _________ of transcription and translation.

b. binding of a tRNA carrying the appropriate amino acid.

In the triplet-binding assay of Nirenberg and Leder, an RNA triplet composed of three bases was able to cause the a. translation of a polypeptide b. binding of a tRNA carrying the appropriate amino acid. c. termination of translation d. release of the amino acid from the tRNA

Cytosol

In which cellular location would ribosomes be found for both prokaryotic and eukaryotic cells? Chloroplasts Cytosol, mitochondria and chloroplasts Mitochondria Mitochondria and chloroplasts Cytosol

a. E site b. P site c. A site

In which of the ribosomal sites, the A site, P site, and/or E site, could the following be found? a. A tRNA without an amino acid attached b. a tRNA with a polypeptide attached c. A tRNA with a single amino acid attached

a. the choice of the start codon in complex eukaryotes

Kozak's rules determine a. the choice of the start codon in complex eukaryotes b. the choice of the start codon in bacteria c. the site in the mRNA where translation ends d. how fast the mRNA is translated

translocation

Movement of the ribosome so that the tRNA in the P site is shifted to the E site while the tRNA in the A site is shifted to the P site is called translocation. termination. elongation. initiation.

pyrrolysine

Pyrrolysine is an α-amino acid that is used in the biosynthesis of proteins in some methanogenic archaea and bacteria; it is not present in humans. It contains an α-amino group, a carboxylic acid group. Its pyrroline side-chain is similar to that of lysine in being basic and positively charged at neutral pH - Encoded by UAG which is normally a stop codon

triplet-binding

Researchers could determine the codon that specified a particular amino acid in an experiment where a three-nucleotide RNA molecule caused a ribosome to bind the tRNA carrying that amino acid. This experimental method is called the _________-_______ assay.

protein synthesis.

Some antibiotics can be used to inhibit the growth of prokaryotic cells without harming their eukaryotic hosts because they are small molecules that bind only to prokaryotic ribosomes preventing the formation of tRNA. protein synthesis. the formation of mRNA. DNA replication.

mRNA to the small ribosomal subunit.

The Shine-Dalgarno sequence facilitates the binding of mRNA to the large ribosomal subunit. the first tRNA to the P site of the ribosome. mRNA to the small ribosomal subunit. the second tRNA to the A site of the ribosome.

mRNA to the small ribosomal subunit.

The Shine-Dalgarno sequence facilitates the binding of mRNA to the small ribosomal subunit. mRNA to the large ribosomal subunit. the second tRNA to the A site of the ribosome. the first tRNA to the P site of the ribosome.

16S

The __________ rRNA of the ribosome will prevent elongation until a mispaired tRNA is released from the A site.

prokaryotic cells. Eukaryotes do not have a 50S subunit. This is why the 50S subunit, found in prokaryotes, is a selective target.

The antibiotic chloramphenicol binds to the 50S ribosomal subunit and prevents the formation of peptide bonds. This would inhibit protein synthesis in eukaryotic cells. neither prokaryotic nor eukaryotic cells. prokaryotic cells. both prokaryotic and eukaryotic cells.

peptide bond.

The bond formed between the carboxylic acid group of one amino acid and the amino group of the next amino acid is a(n) phosphodiester bond. ionic bond. hydrogen bond. peptide bond.

polysome

The combination of a messenger RNA and many bound ribosomes in the process of translation is called a(n) ___________.

ribosome

The complex of rRNA and protein that acts as the site of translation is the ___________.

a protein called release factor.

The component that recognizes a stop codon at termination of translation is peptidyl transferase. 23S rRNA. 16S rRNA a protein called release factor. a terminating transfer RNA.

primary

The consecutive order of amino acids in a polypeptide chain represents its ___________ structure.

tertiary

The folded-three dimensional conformation of a polypeptide represents its ____________ structure.

tertiary structure.

The folding of α helical regions and beta-sheet regions relative to each other leads to formation of a polypeptide's quaternary structure. secondary structure. tertiary structure. primary structure.

tertiary structure.

The folding of α helical regions and beta-sheet regions relative to each other leads to formation of a polypeptide's secondary structure. tertiary structure. primary structure. quaternary structure.

secondary

The initial folding of a polypeptide into a regular repeating shape represents its _______ structure.

Termination

The newly produced polypeptide is released from the ribosome.

anticodon

The order in which amino acids are added to a polypeptide chain is determined by hydrogen bonding between each codon and the ______ of the tRNA carrying the amino acid. anticodon stem-loop structures acceptor stem 5' end variable bases

quaternary structure.

The oxygen-carrying molecule hemoglobin is an association of four polypeptides, two called α-hemoglobin and two called β-hemoglobin. The level of protein structure demonstrated by hemoglobin is quaternary structure. primary structure. tertiary structure. secondary structure.

secondary structure.

The protein structure stabilized by the formation of hydrogen bonds between atoms found in the polypeptide backbone is secondary structure. quaternary structure. tertiary structure. primary structure.

A start codon (AUG)

The reading frame begins with what?

Primary structure

The sequence of amino acids that results from gene transcription and mRNA translation represents which structure of the protein? Tertiary structure Quaternary structure Secondary structure Primary structure

stop

The signal for termination of translation is called a(n) _________ codon.

elongation

The stage of translation in which amino acids are added one at a time to a growing polypeptide chain is called __________.

translation

The synthesis of a protein using the sequence of codons in a messenger RNA is called __________.

isoacceptor tRNAs

The term "___________" is used for chemically different species of tRNA which are acylated by the same amino acid. It is clear that the degeneracy of the genetic code requires the presence of isoacceptor tRNA's.

R group.

The unique chemical properties of each amino acid are determined by its R group. central carbon. carboxylic acid group. amino group.

adaptor hypothesis.

To account for the involvement of RNA molecules for incorporating amino acids into a protein chain, Francis Crick proposed the base-pairing hypothesis. adaptor hypothesis. genetic code hypothesis. wobble hypothesis.

A

To begin each round of elongation during translation, the tRNA carrying the next amino acid to be added to the polypeptide chain binds to the ______________ site of the ribosome.

Anticodon

To bring a specific amino acid into its location on a polypeptide chain, which sequence on transfer RNA must bind to messenger RNA? 3' sequence 5' sequence Codon Anticodon

Anticodon

To bring a specific amino acid into its location on a polypeptide chain, which sequence on transfer RNA must bind to messenger RNA? 3' sequence Codon Anticodon 5' sequence

an enzyme that would metabolize homogentisic acid.

To explain why patients had a buildup of the urine-darkening metabolite homogentisic acid, Archibald Garrod proposed that they were lacking receptors for homogentisic acid. ribosomes to make metabolic enzymes. mitochondria. an enzyme that would metabolize homogentisic acid.

initiation, elongation, termination

Translation is divided into three stages: the first is ________, the next is ___________, and the last is _________.

ribosome

Translation takes place on a structure called the __________.

False There are regions on the mRNA that precede the start codon and follow the stop codon, they are called the 5' UTR and 3' UTR respectively.

True or false: The entire mRNA molecule encodes a polypeptide. True False

codons

What are the three base units called that are read on the mRNA transcript?

Anticodons

What do the three base units (codons) match on the tRNA?

Peptide bond

What is the name for the type of bond that joins the amino acids shown by the arrows in the diagram? Phosphodiester bond Peptide bond Hydrogen bond Ionic bond

Aminoacyl-tRNA synthetases (AARSs) are the enzymes that catalyze the aminoacylation reaction by covalently linking an amino acid to its cognate tRNA in the first step of protein translation. the features of a tRNA molecule that make it recognizable by one amino acid synthetase but not by others.

What is the role of aminoacyl-tRNA synthetase? the ability of aminoacyl-tRNA synthetases to recognize tRNAs has sometimes been called the "second genetic code". Why has the function of this type of enzyme been described this way?

Peptidyl transferase catalyzes peptide bond formation between amino acids in the growing polypeptide

What is the role of peptidyl transferase during the elongation stage

280

When the ribosome synthesizes a 281-amino acid polypeptide, ___________ rounds of elongation are required.

selenocysteine and pyrrolysine

Which are the twenty-first and twenty-second amino acids that can be used in protein synthesis? selenocysteine and pyrrolysine acetylserine and acetylthreonine phosphocysteine and acetyl-lysine hydroxyproline and homoserine

3' UTR 5' UTR

Which areas of an mRNA molecule do not encode a polypeptide? 3' UTR Coding region 5' UTR

16S rRNA

Which component of the ribosome can recognize a tRNA that is not correctly matched with an mRNA codon? 16S rRNA 5S rRNA 50S ribosomal subunit 23S rRNA 30S ribosomal subunit

Triplet-binding assay

Which method uses a three-nucleotide RNA molecule to cause a ribosome to bind the tRNA carrying that amino acid? Triplet-binding assay Cell-free translation of copolymers Amino acid-binding assay Cell-free translation of synthetic mRNA mixtures Codon-binding assay

U

Which nucleotide in a tRNA anticodon would bind to the A nucleotide in an mRNA codon? G T A U C

A

Which nucleotide in a tRNA anticodon would bind to the U nucleotide in an mRNA codon? T A G C U

tRNAf-Met as the initiator tRNA IF1, IF2 and IF3 as initiation factors Shine-Dalgarno sequence to facilitate mRNA binding to the small ribosomal subunit

Which of the following is used in prokaryotic translation but not in eukaryotic translation? tRNAf-Met as the initiator tRNA 80S ribosomes IF1, IF2 and IF3 as initiation factors 7-methylguanosine cap on mRNA to facilitate binding to the small ribosomal subunit Shine-Dalgarno sequence to facilitate mRNA binding to the small ribosomal subunit

An 80S ribosome is used for translation Start codon is selected according to Kozak's rules Release factors eRF1 and eRF3 are required

Which of the following occurs in eukaryotic translation but not in prokaryotic translation? An 80S ribosome is used for translation Start codon is selected according to Kozak's rules Release factors eRF1 and eRF3 are required Translation begins before transcription has been completed tRNAf-Met is the initiator tRNA

Three stem-loops A small number of variable sites Amino acid acceptor stem with a 3' single-stranded region Anticodon sequence

Which of the following represent common structural features of transfer RNA molecules? Three stem-loops A small number of variable sites Codon sequence to specify which amino acid will bind Amino acid acceptor stem with a 3' single-stranded region Anticodon sequence

Triplet-binding assays to determine which transfer RNAs bind to specific codons Cell-free translation experiments using synthetic messenger RNAs Cell-free translation experiments using RNA copolymers with repeating patterns of nucleotides

Which of the following were used in the efforts to decipher the genetic code? Triplet-binding assays to determine which transfer RNAs bind to specific codons Cell-free translation experiments using synthetic messenger RNAs In vitro assays of specific tRNA and mRNA binding interactions Cell-free translation experiments using RNA copolymers with repeating patterns of nucleotides In vitro transcription assays to show which types of mRNA are produced

Codon to specify which amino acid will be attached

Which one is NOT found in all transfer RNA molecules? Amino acid acceptor stem with a 3' single-stranded region Anticodon One or more variable sites Codon to specify which amino acid will be attached Stem-loop structures, with stabilized by hydrogen bonding on the stems

Hydrophobic

Which type of R group is consistent with an amino acid that is found in the interior of a folded protein? Neither hydrophobic nor hydrophilic Hydrophobic Both hydrophobic and hydrophilic Hydrophilic

Hydrophilic

Which type of R group is consistent with an amino acid that is found on the exterior of a folded protein? Neither hydrophilic nor hydrophobic Hydrophobic Hydrophilic Both hydrophilic and hydrophobic

Transfer RNA

Which type of RNA is shown in the figure? Messenger RNA Ribosomal RNA Transfer RNA

Sense codon

Which type of codon would lead to the placement of a specific amino acid such as leucine into the polypeptide sequence? Start codon Nonsense codon Sense codon Stop codon

adaptor hypothesis

a hypothesis that proposes a tRNA has two functions: recognizing a three-base codon sequence in mRNA and carrying an amino acid that is specific for that codon

c. both a and b are secondary structures in proteins

a type of secondary structure found is proteins in a. an alpha helix b. a beta sheet c. both a and b are secondary structures in proteins d. neither a nor b is a secondary structure

b. aminoacyl-tRNA synthetase, 3' single-stranded region of the acceptor stem, a charged tRNA

an enzyme known as ________ attaches an amino acid to the _________ of a tRNA, thereby producing ________ a. aminoacyl-tRNA synthetase, anticodon, a charged tRNA b. aminoacyl-tRNA synthetase, 3' single-stranded region of the acceptor stem, a charged tRNA c. polynucleotide phosphorylase, anticodon, a charged tRNA d. polynucleotide phosphorylase, anticodon, an aminoacyl tRNA

a. a mutation in a gene that causes an enzyme to be inactive

an inborn error of metabolism is caused by a. a mutation in a gene that causes an enzyme to be inactive b. a mutation in a gene that occurs in somatic cells c. the consumption of foods that disrupt metabolic processes d. any of the above

Selenocysteine

an unusual amino acid of proteins, the selenium analogue of cysteine, in which a selenium atom replaces sulphur. Involved in the catalytic mechanism of seleno enzymes such as formate dehydrogenase of E. coli and mammalian glutathione peroxidase. - found in several enzymes of redox reactions - encoded by UGA which is normally a stop codon

the role of DNA is to store the information that specifies the amino acid sequence of a polypeptide

describe the role of DNA in the synthesis of a polypeptide

a site in mRNA promotes the binding of the mRNA to the ribosome during formation of the initiation complex. During elongation, the codons in the mRNA specify the polypeptide sequence. The stop codon of mRNA is needed to terminate transcription.

describe the roles that mRNA plays in the three stages of translation

d. both a and b

each ribosomal unit is composed of a. multiple proteins b. rRNA c. tRNA d. both a and b

The wobble rules allow for a smaller population of tRNAs to recognize all of the possible mRNA codons

how do the wobble rules affect the total number of different tRNAs that are needed to carry out translation

b. leucine

if a tRNA has an anticodon with the sequence 5'-CAG-3', which amino acid does it carry? a. aspartic acid b. leucine c. valine d. glutamine

c. 2.7%

let's suppose a researcher mixed together nucleotides with the following percentage of bases: 30% G, 30% C, and 40% A. If RNA was made via polynucleotide phosphorylase, what percentage of the codons would be 5'-GGG-3'? a. 30% b. 9% c. 2.7% d. 0%

c. loop of the second stem-loop

the anticodon of a tRNA is located in the a. 3' single-stranded region of the acceptor stem b. loop of the first stem-loop c. loop of the second stem-loop d. loop of the third stem-loop

b. the fourth amino acid from the N-terminus is glycine

the fourth codon in an mRNA is GGG, which specifies glycine. If we assume that no amino acids are removed from the polypeptide, which of the following statements is correct? a. the third amino acid from the N-terminus is glycine b. the fourth amino acid from the N-terminus is glycine c. the third amino acid from the C-terminus is glycine d. The fourth amino acid from the C-terminus is glycine

d. start codon in groups of three bases

the reading frame begins with a _______ and is read _____________ a. promoter, one base at a time b. promoter, in groups of three bases c. start codon, one base at a time d. start codon in groups of three bases

c. four different enzymes are involved in a pathway for methionine biosynthesis

the reason why beadle and tatum observed four different categories of mutants that could not grow on media without methionine is a. the enzyme involved in methionine biosynthesis is composed of four different subunits b. the enzyme involved in methionine biosynthesis is present in four copies in the neurospora genome c. four different enzymes are involved in a pathway for methionine biosynthesis d. a lack of methionine biosynthesis can inhibit neurospora growth in four different ways

d. all of the above

the site(s) on a ribosome where tRNA molecules may be located include a. the A site b. the P site c. the E site d. all of the above

degenerate code (redundant)

there are more codons (64) than there are amino acids to be coded, so most amino acids are coded by more than one code.

a tRNA has an anticodon that recognizes a codon in the mRNA. It also has a 3' acceptor site where the correct amino acid is attached

what are the two key functional sites of a tRNA molecule

a charged tRNA has an amino acid attached to it

what is the difference between a charged tRNA and an uncharged tRNA

a. the relationship between a three-base codon sequence and an amino acid or the end of translation

what is the genetic code a. the relationship between a three-base codon sequence and an amino acid or the end of translation b. the entire base sequence of an mRNA molecule c. the entire sequence from the promoter to the terminator of a gene d. the binding of tRNA to mRNA

21 nm sediment coefficient: 705 number of proteins: 55

what is the ribosome size of a bacterium?

between 25 and 30 nm sediment coefficient: 805 number of proteins: 82

what is the ribosome size of a eukaryotic cell?

hydrogen bonding promotes the formation of secondary structures in proteins

what type of bonding is responsible for the formation of the two types of secondary structures (alpha helix and beta pleated sheets)

Alkaptonuria

which disease occurs when homogentisic acid oxidase is defective

the Shine-Dalgarno sequence in bacterial mRNA is complementary to a region in the 16S rRNA within the small ribosomal subunit. These complementary sequences hydrogen bond with each other

why does bacterial mRNA bind specifically to the small ribosomal subunit