RNA DnA

Question 1

RNA molecules that exhibit catalytic activity are called

Answer 1

Ribozymes

Question 2

2. Which of the following hormones initiates biological actions by crossing the plasma membrane or then binding to a receptor?
   a. glucagon
   b. estradiol
   c. insulin
   d. norepinephrine
   e. adrenocorticotropic hormone

Answer 2

estradiol

Question 3

3. Diacylglycerol activates which of the following enzymes?
   a. protein kinase C
   b. protein kinase A
   c. MAP kinase
   d. tyrosine kinase
   e. phosphoinositide 3 kinase

Answer 3

protein kinase C

Question 4

4. Which of the following is NOT involved in the processing of mRNA precursors in the eukaryotic cell?
   a. capping of the 5’ end
   b. addition of poly(A)
   c. splicing of exons
   d. removal of introns
   e. transport of the pre-mRNA to the cytoplasm

Answer 4

Transport of the pre-mRNA to the cytoplasm

Question 5

5. What is the most positive activator of the process shown below?
   8 acetylCoA + nATP} + 14 NADPH} ~ palmitate} + 8 CoASH + nADP} + nPi + NADP

a. acetylCoA
b. citrate
c. malonylCoA
d. malate
e. acetoacetate

Answer 5

Citrate

Question 6

6. Which enzymes are responsible for producing the direct donors of nitrogen into the pathway producing urea?
   a. arginase and argininosuccinate lyase
   b. glutamate dehydrogenase and glutamine amidotransferase
   c. argininosuccinate synthetase and ornithine transcarbamoylase
   d. aspartate amino transferase and carbamoylphosphate synthetase

Answer 6

Arginase and argininosuccinate lyase

Question 7

The carbon atoms of cholesterol are derived from

Answer 7

Acetyl CoA

Question 8

which are the following enzymes require adenosine triphosphate to mediate its reaction. A. Argininosuccinate lyase, B. Argininosuccinate synthetase, C. Arginase, D. Glutaminase, E. Ornithin transcarbamolase

Answer 8

B. Argininosuccinate synthetase

Question 9

Which of the following is a common nitrogen acceptor for all reactions involving transaminases? a. α-ketoglutarate b. pyruvate c. oxaloacetate d. acetoacetate

Answer 9

Alpha ketoglutarate

Question 10

Which of the following is a common nitrogen acceptor for all reactions involving transaminases? a. α-ketoglutarate b. pyruvate c. oxaloacetate d. acetoacetate

Answer 10

alpha ketoglutarate

Question 11

Which out of the following compounds are synthesized by transmethylation reactions except A. Choline, B. Epinephrine, C. Creatine, D. Ethanolamin

Answer 11

Ethanolamine

Question 12

which of the following statements concerning RNA and DNA polymerases is correct

Answer 12

All RNA and DNA polymerase’s can add nucleotides only add to the 3’ end of the growing polynucleotide chain

Question 13

Initiation of protein synthesis begins with with the binding of

Answer 13

40 S ribosomal unit on mRNA