Gene Expression and Protein Synthesis

Question 1

Where does all protein synthesis begin?

Answer 1

Cytosol

Question 2

alternative splicing

Answer 2

can give several different mRNAs from the same gene

Question 3

ends of mRNA

Answer 3

5’ cap and poly A tail

Question 4

RNA editing

Answer 4

enzymatic activity that alters one mRNA AFTER splicing but before it leaves the nucleus

changes only one RNA

Question 5

promoter

Answer 5

where transcription factors bind (Pol II)

Question 6

p53

Answer 6

tumor suppressor protein

most tumors that affect humans involve some MUTATION of p53

Question 7

P21

Answer 7

p53 regulator

Question 8

p21 regulation of p53

Answer 8

p21 gives cell a chance to correct mistakes before they alter the cell in some terrible way

if can’t fix, then p53 will continue and apoptosis occurs

Question 9

mdm-2

Answer 9

protein transcribed by p53

Question 10

mdm2 feedback inhibition

Answer 10

can bind to p53 and cause degradation by adding ubiquitones to it and making it a target

this happens when tumor suppressor is not needed

example of product inhibiting its own synthesis

Question 11

polymerase I

Answer 11

transcribes ribosomal RNA

Question 12

polymerase III

Answer 12

transcribes tRNA

Question 13

polymerase II

Answer 13

transcribes mRNA and several of the small structural RNA’s (sn and sc)

Question 14

5’ cap

Answer 14

increases the efficiency of the mRNA in translation and protects the nascent RNA from degradation in the nucleus

Question 15

Poly A tail

Answer 15

transport of mature mRNA from nucleus

can protect mRNA from degradation

can serve as a recognition signal for ribosomes

Question 16

splicing

Answer 16

removal of introns from mRNA

Question 17

promoter

Answer 17

specific sequences that regulate RNA transcription at the level of RNA polymerase binding

TATA box

CAAT box

Question 18

Enhancer

Answer 18

variable sequence frequently far away from the initiation site

Question 19

transcription factors

Answer 19

how proteins regulate transcription of specific genes

Question 20

positive regulators

Answer 20

binding of specific proteins are necessary for RNA polymerase binding and transcription initiation

Question 21

repressors

Answer 21

binding of specific proteins to DNA prevents binding of RNA polymerase

Question 22

HPV effect on p53

Answer 22

contains E6 and 7 which target p53 for degradation

this is bad when p53 is needed to suppress cancer!!!!

Question 23

what is the rate-limiting step in translation?

Answer 23

initiation

Question 24

what are the 3 steps of translation?

Answer 24

initiation

elongation

termination

Question 25

where are free proteins synthesized?

Answer 25

cytosol

Question 26

where are membrane and secreted proteins synthesized?

Answer 26

Rough ER

Question 27

what is produced in the smooth ER

Answer 27

lipids

Question 28

signal sequence

Answer 28

tells ribosomes to associate with ER to form membrane and secreted proteins

Question 29

signal recognition particle

Answer 29

temporarily stops translation and recognizes docking proteins in the ER

Question 30

vectorial discharge

Answer 30

protein inhection through ER in an energy dependent (ATP) manner

Question 31

KDEL sequence

Answer 31

for proteins to remain in the ER

Question 32

chaperone protein

Answer 32

assist in folding process

Question 33

hsp proteins

Answer 33

assist in folding and provide protective mechanism when cell heats up

Question 34

polysome

Answer 34

several ribosomes reading the same message