CHAPTER V: TRANSCRIPTION AND TRANSLATION (MODULE) part 3

Question 1

Translation of mRNA is the biological __________ of amino
acids into ________. This process occurs only in association with _____________, which serve as ________________

Answer 1

polymerization
polypeptide chains
ribosomes
nonspecific workbenches

Question 2

In association with a ribosome, mRNA presents a ____________
that calls for a specific amino acid. A specific tRNA molecule contains within its nucleotide sequence three consecutive ___________complementary to the codon, called the ___________, which can base-pair with the codon. Another region of this tRNA is __________bonded to the codon’s corresponding amino acid.

Answer 2

triplet codon
ribonucleotides
anticodon
covalently

Question 3

____________ of tRNAs to mRNA holds amino acids in proximity to each other so that a peptide bond can be formed between them. The process occurs over and over as mRNA runs through the ribosome, and amino acids are polymerized into a polypeptide. Before looking more closely at this process, we will
first consider the __________ - of the ribosome and transfer RNA.

Answer 3

Hydrogen bonding
structures

Question 4

Ribosomes, when they are not involved in translation, are
dissociated into their large and small subunits.

Answer 4

INITIATION

Question 5

Initiation of translation in E. coli involves the small ribosomal subunit, an mRNA molecule, a specific charged initiator _______________, and three proteinaceous initiation factors (IFs) that enhance the binding affinity of the various translational components and facilitate the process.

Answer 5

tRNA, GTP, Mg2+

Question 6

In prokaryotes, the initiation codon of mRNA—AUG—calls for the modified amino acid ______________ (f-met).

Answer 6

N- formylmethionine

Question 7

Lengthening of the growing polypeptide chain by one amino acid.

Answer 7

ELONGATION

Question 8

the third phase of translation.

Answer 8

TERMINATION

Question 9

These codons do not specify an amino acid, nor do they call for a tRNA in the A site. They are called __________________?

Answer 9

stop codons, termination codons, or nonsense codons.

Question 10

Often, several consecutive stop codons are part of an mRNA. When one such termination stop codon is
encountered, the polypeptide, now completed, is still part of the ________ tRNA in the P site, and the A site is _______.

Answer 10

peptidyl
empty

Question 11

The termination codon signals the action of a _____________ release factor, which stimulates ___________of the polypeptide from the peptidyl tRNA, leading to its release from the translation complex (Step 1). Then, the ___________ is released from the ribosome, which then dissociates into its subunits (Step 2).

Answer 11

GTP-dependent
hydrolysis
tRNA