Quiz 11

What is the final component of the initiation complex to be added? A) GTP B) a large subunit of the ribosome C) a small subunit of the ribosome D) the mRNA E) an initiator tRNA

B) a large subunit of the ribosome

A tRNA anticodon is 5'-CAU- 3'. What amino acid does it carry? A) ala B) met C) ser D) pro E) thr

B) met

Myoglobin is a protein in muscle cells that consists of a single polypeptide. If you are concerned with interactions between amino acids that stabilize its overall three-dimensional structure in muscle cells, you are concerned with its _____________ structure. A) quaternary B) tertiary C) secondary D) primary E) None of the above

B) tertiary

Which of the following need(s) to be able to recognize and match correctly an anticodon and an amino acid? A) Aminoacyl-tRNA synthetase B) Codon C) mRNA D) Ribosome E) More than one of the above

A) Aminoacyl-tRNA synthetase

Which statement about the genetic code is not true? A) Some codons can specify more than one amino acid. B) The genetic code is the same or very similar in all species examined so far. C) The genetic code includes start and stop signals. D) The genetic code is read in groups of three adjacent nucleotides. E) Most amino acids are specified by more than one codon.

A) Some codons can specify more than one amino acid.

Side groups of amino acids are typically classified under which of the following? A) polar, nonpolar B) linear, circular C) alpha, omega D) long, short E) primary, secondary

A) polar, nonpolar

The formation of peptide bonds during elongation is catalyzed by an enzyme called the ribozyme. The ribozyme is made of what macromolecule? A) rRNA in the large subunit of the ribosome B) protein in the large subunit of the ribosome C) protein in the small subunit of the ribosome D) rRNA in the small subunit of the ribosome E) tRNA

A) rRNA in the large subunit of the ribosome

If instead of 20 amino acids there were 200 amino acids, then how many nucleotides would you predict to be in a codon? A) 2 B) 3 C) 4 D) 5 E) 6

C) 4

Which statement is true regarding the binding of an amino acid to a tRNA? A) Amino acids bind to the 5′ end of the tRNA. B) The binding of amino acids to tRNAs requires GTP. C) There is one aminoacyl tRNA synthetase for each of the 20 amino acids. D) Each aminoacyl tRNA synthetase recognizes a different tRNA. E) Both c and d.

C) There is one aminoacyl tRNA synthetase for each of the 20 amino acids.

To translate a mRNA you require two other RNAs. These are A) tRNA and mRNA. B) tRNA and miRNA. C) tRNA and rRNA. D) rRNA and siRNA.

C) tRNA and rRNA.

By their experimentation using the Neurospora fungus, Beadle and Tatum were able to propose the far-reaching hypothesis that ________. A) prototrophs will grow only if provided with nutritional supplements B) several different enzymes may be involved in the same step in a biochemical pathway C) the role of a specific gene is to produce a specific enzyme D) genetic recombination occurred in Neurospora E) more than one codon can specify a given amino acid

C) the role of a specific gene is to produce a specific enzyme

The secondary structure of a protein includes ________. A) gamma and delta B) alpha and gamma C) α-helix and β-pleated sheet D) hydrophobic clusters E) disulfide bridges

C) α-helix and β-pleated sheet

A yeast strain was exposed to a chemical mutagen. As expected, exposure to mutagen resulted in a DNA sequence change within the coding region of an essential gene you examined. Yet, this mutation did not result in any lethal phenotype. How could you explain this apparent discrepancy? A) It was a nonsense mutation B) It was a missense mutation C) It was a synchronous mutation D) It resulted in a synonymous codon E) None of the above

D) It resulted in a synonymous codon

A bacterial protein is encoded by the following mRNA sequence: 5'AUGGUGCUCAUGCCCTAA3'.... The second methionine codon (AUG) in this mRNA sequence will A) serve as the initiation codon. B) encode N-formylmethionine. C) encode methionine that will eventually be removed. D) encode unformylated methionine.

D) encode unformylated methionine.

What cellular structure helps properly fold some proteins? A) ribosomes B) ribozymes C) signal sequences D) molecular chaperones E) nuclear chaperones

D) molecular chaperones

An mRNA has the stop codon 5'-UAA-3'. What tRNA anticodon will bind to it? A) 5'-ATT- 3' B) 5'-AUC- 3' C) 5'-ACU- 3' D) none

D) none

The wobble rules account for non-Watson and Crick nucleotide pairing at which position of the codon and anticodon, respectively? A) first and third B) first and second C) second and second D) third and first E) third and second

D) third and first

What is the minimum number of different aminoacyl-tRNA synthetases required by a cell? A) 64, one for each codon B) 61, one for each sense codon C) 30, one for each different tRNA D) 50, one for each different tRNA E) 20, one for each amino acid

E) 20, one for each amino acid

What is the function of peptidyl transferase activity? A) It charges tRNAs. B) It acetylates the end of a protein after translation. C) It cleaves the polypeptide from the last tRNA during termination. D) It moves ribosomes along mRNA during translation. E) It forms peptide bonds.

E) forms peptide bonds

A short segment of an mRNA molecule is shown below. The polypeptide it codes for is also shown:5'-AUGGUGCUGAAG-3' : methionine-valine-leucine-lysineAssume that a mutation in the DNA occurs so that the fourth base (counting from the 5' end) of the messenger RNA now reads A rather than G. What sequence of amino acids will the mRNA now code for? A) methionine-valine-leucine-lysine B) methionine-lysine-leucine-lysine C) methionine-leucine-leucine-lysine D) methionine-valine-methionine-lysine E) methionine-methionine-leucine-lysine

E) methionine-methionine-leucine-lysine