Nucleotide Metabolism

Question 1

Nucleotides are structural components of?

Answer 1

DNA and RNA

Question 2

Nucleotides are carriers of _____ _____

Answer 2

activated intermediates

Question 3

Name some coenzymes where nucleotides serve as the structural components.

Answer 3

• CoA
• FAD
• NAD+
• NADP+

Question 4

Nucleotides also serve as _____ in signal transduction

Answer 4

second messengers (ex. cAMP, cGMP)

Question 5

Nucleotides serve as the ______ of the cell

Answer 5

energy currency (ATP)

Question 6

Nucleotides are ______ of many pathways

Answer 6

Regulators

Question 7

Describe the structure/features of nucleotides.

Answer 7

Nitrogenous base + Sugar

Question 8

Name two different types of nitrogenous bases.

Answer 8

Purines and Pyrimidines

Question 9

What bases make up the purines?

Answer 9

Adenine and Guanine

Question 10

What bases make up the pyrimidines?

Answer 10

Cytosine, Thymine (DNA) and Uracil (RNA)

Question 11

Describe the two different types of sugar molecules in nucleotides?

Answer 11

Ribose in RNA and deoxyribose in DNA

Question 12

Describe a nucleoside.

Answer 12

Nitrogenous Base + Sugar

Question 13

Describe a Nucleotide

Answer 13

Nucleoside + 1-3 phosphate groups

Question 14

The _______ bonds linking the 2nd and 3rd phosphate on the nucleoside triphosphate are the high energy bonds driving many chemical reactions

Answer 14

Anhydride

Question 15

In Purine Nucleotide Synthesis:

The _________ comes from the HMP Shunt Pathway

Answer 15

Ribose 5-phosphate

Question 16

In Purine Nucleotide Synthesis:

Step 1: __________ catalyzes the formation of the activated pentose (Phosphoribosyl-pyrophosphate)

Answer 16

PRPP synthetase

Question 17

List the activators (+) and inhibitors (-) of PRPP synthetase.

Answer 17

Activator: Inorganic Phosphate
Inhibitor: Purine Ribonucleotides

Question 18

The _______ is attached at the 1’ carbon, which is where the nitrogenous base will be attached.

Answer 18

pyrophosphate

Question 19

The rate limiting step is catalyzed by ___________ (regluated, committed step_

Answer 19

PRPP Amidotransferase

Question 20

_____ is also required for subsequent as a carbon dimer

Answer 20

Folate

Question 21

________ is required to make THF (tetrahydrofolate), the form in which folate is used

Answer 21

Dihydrofolate reductase

Question 22

In subsequent steps, the amino acids:

_____, _____ and ______ become part of the nitrogenous base structure

Answer 22

glycine, aspartate, glutamine

Question 23

PRPP Amidotransferase regulation:

Answer 23

inhibited by purine nucleotides (end products)

activated by PRPP (substrate)