Chapter 15 Quiz

Which does the termination of translation require?

- GTP - release factors - stop codon on the mRNA

Proteins are composed of ___ linked together by ___ bonds

- amino acids - peptide bonds

There are 64 codons, 20 different amino acids, and approximately 30-50 tRNAs. Which statements help explain these numbers?

- isoaccepting tRNAs can carry the same amino acid - flexibility, or wobble, between the anticodon and the codon allows one tRNA to pair with multiple codons - many amino acids are coded for by more than one of the 61 sense codons - synonymous coons code for the same amino acid

Which of the options are mechanisms of mRNA surveillance?

- nonsense-mediated mRNA decay - no-go decay - nonstop mRNA decay

Aminoacyl-tRNA synthetases recognize their specific amino acid by ___ and recognize the tRNAs that carry it by the ___.

- size, charge, and R group - nucleotide sequence

Which of the statements about the genetic code are most accurate?

- the genetic code is generally non-overlapping - an initiation codon sets the reading frame

Which statement is most consistent with the one gene, one enzyme hypothesis originally proposed by Beadle and Tatum?

Every gene encodes a separate enzyme

There are 64 codons, 20 different amino acids, and approximately 30-50 tRNAs. Which statement does NOT help explain these numbers

The 3' base of the anticodon on the tRNA can pair weakly with the 5' codon base

Which of these is the first step of translation elongation?

a charged tRNA binds to the A site

The discovery that some proteins are composed of more than one polypeptide chain and that different polypeptide chains are encoded by separate genes became the what?

one gene, one polypeptide hypothesis

When mRNAs are being translated simultaneously by multiple ribosomes, the structure is known as

polyribosome

Te way that proteins fold into beta pleated sheets and alpha helices is dependent on their

primary structure

The bacterial transfer-messenger RNA system

removes stalled ribosomes in bacteria

Which of these is not involved in the initiation of translation in bacteria?

tRNA carrying the next amino acid that will occupy the A site

What is the first stage of protein synthesis?

tRNA charging, in which the tRNAs bind to amino acids

Which component of translation is frequently targeted by antibiotics?

the ribosome