M11

Question 1

Functions of RNA polymerase include:

Answer 1

searching for promoter sites, unwinding short stretches of DNA, detecting termination signals

Question 2

For transcription to occur, the structure of DNA must be in

Answer 2

the open promoter complex.

Question 3

The Pribnow box

Answer 3

is the site where RNA polymerase binds.

Question 4

The protein that binds DNA sequences and helps RNA polymerases initiate transcription is:

Answer 4

σ

Question 5

What RNA sequences are spliced out of mature eukaryotic mRNA molecules?

Answer 5

Introns

Question 6

The processivity of transcribing RNA polymerase is approximately

Answer 6

essentially infinite

Question 7

The proteins that bind DNA at eukaryotic promoters to form the initiation complex are called

Answer 7

transcription factors

Question 8

Which of the following modifications are made to eukaryotic tRNA transcripts?

Answer 8

modification of base and ribose moieties

removal of the 3´ trailer

cleavage of the 5´ leader by RNase P

CCA is added.

Question 9

Intron splicing is catalyzed by of the spliceosome which is made up of a class of ribonucleoprotiens called

Answer 9

snRNPs

Question 10

Much of the protein diversity present in our cells is generated by

Answer 10

alternative splicing of exons

Question 11

Protein synthesis takes place on

Answer 11

ribosomes

Question 12

The start signal for most organisms is

Answer 12

AUG

Question 13

The actual three-dimensional structure of tRNA is a(n):

Answer 13

L-shape

Question 14

The observation that the last nucleotide in a codon can basepair with more than one base in the tRNA anticodon is the basis for the

Answer 14

Wobble hypothesis.

Question 15

Amino acids are attached to tRNA molecules at the ____________________ or _____________________ stem.

Answer 15

CCA or acceptor

Question 16

Aminoacyl-tRNA synthetases contain both an activation site and a(n) __________________ site.

Answer 16

editing

Question 17

The 70S bacterial ribosome is composed of a 50S and 30S subunit. What is the function of the 30S subunit in translation?

Answer 17

tRNA recognition

alignment of the mRNA on the ribosome to initiate translation

Question 18

Which of the following is/are required for the initiation of protein synthesis in prokaryotes?

Answer 18

mRNA

The 30S subunit

fMet-tRNAf

GTP

Question 19

What is the direction of translation of mRNA?

Answer 19

5′ → 3′

Question 20

Signals that define the beginning and end of protein synthesis are contained in

Answer 20

mRNA

Question 21

Eukaryotic and prokaryotic translation differs primarily in which step?

Answer 21

Initiation

Question 22

Which of the following E. coli proteins is responsible for translocation of the mRNA as a result of a conformation change due to the hydrolysis of GTP?

Answer 22

EF-G

Question 23

The three stages of RNA synthesis are _________________________, __________________________, and ____________________________.

Answer 23

Initiation, elongation, termination

Question 24

Eukaryotic RNA polymerases differ in their sensitivity to the mushroom toxin _____________________.

Answer 24

α-amanitin

Question 25

What are the names for the tRNA binding sites on the ribosome? ___________________________, ___________________________, and ________________________________.

Answer 25

A, P, E or aminoacyl, peptidyl, exit