Gene Regulation And Protein Synthesis

Question 1

What do RNA polymerases do?

Answer 1

Bind to promoters to initiate transcription

Question 2

What are RNA polymerases?

Answer 2

Multi subunit complexes which make up RNA

Question 3

What is TFIID?

Answer 3

General transcription factor

Question 4

Role of TATA box binding protein in transcription:

Answer 4

Introduces kink to DNA to determine start and direction of transcription
Provides landing platforms for transcription factors and RNA polymerase

Question 5

What is elongation in transcription?

Answer 5

Addition of nucleotides to RNA chain in 5’-3’ direction

Question 6

Termination in translation:

Answer 6

Site encounters stop codon
Termination protein binds to codon
Ribosome dissociates
Causes change in transferase
tRNA releases protein

Question 7

What is initiation in translation?

Answer 7

Formation of initiation complex
Energy provided by GTP
Requires additional general transcription factors

Question 8

Role of rRNA

Answer 8

Combines with proteins to form ribosomes

Question 9

Role of tRNA

Answer 9

Carries amino acids to be incorporated into proteins

Question 10

Role of mRNA

Answer 10

Carries genetic information for protein synthesis

Question 11

What are the 3 types of RNA polymerases in eukaryotes?

Answer 11

Pol I
Pol II
Pol III

Question 12

Termination in transcription:

Answer 12

Release of finished RNA

Question 13

Role of Aminoacyl-tRNA synthetases

Answer 13

Catalyses covalent attachment of amino acids to their corresponding tRNA molecule

Question 14

What is elongation in translation?

Answer 14

Anticodons of tRNA form base pairs with codons on mRNA

Question 15

Role of Peptidyl transferase

Answer 15

Catalyses peptide bond formation between amino acids in P and A sites

Question 16

Role of EF-2

Answer 16

moves ribosomes along mRNA

Question 17

Post translational modifications (4):

Answer 17

Glycosylation
Disulphide bonds (ER)
Folding/assembly of multi-subunit proteins (ER)
Specific proteolytic cleavage (ER, Golgi)

Question 18

What are the 3 tRNA binding sites?

Answer 18

P (peptidyl site)
A (acceptor site)
E (exit site)

Question 19

What do free ribosomes in cytoskeleton produce?

Answer 19

Proteins for cytosol, nucleus, and mitochondria

Question 20

What do bound ribosomes on rough ER produce?

Answer 20

Proteins for plasma membrane, ER, Golgi

Question 21

Point mutation

Answer 21

Change in single base