4 Biosynthesis & Degradation of Nucleic Acids

Question 1

What is the precursor molecule of all pyramidine nucleotides?

Answer 1

UMP

Uridine Monophosphate

Question 2

A phosphorylated nucleoside is known as a:

Answer 2

Nucleotide

Question 3

Formation of what molecule is the first step in de novo purine ring synthesis?

Answer 3

IMP

Inosine Monophosphate

Question 4

How do proteins of cytosolic origin enter the mitochondria?

Answer 4

TIM and TOM channels

Question 5

The bonds between pairs of nucleotides in a complete DNA molecule are Hydrogen bonds; the bonds between the deoxyribose molecules are ________.

Answer 5

Covalent bonds

Question 6

IMP does not accumulate significantly in the cell after production, to what molecules is it converted?

Answer 6

AMP and GMP

Question 7

Nucleosides are a combination of which two molecules?

Answer 7

Nitrogenous base and a five carbon sugar

Question 8

What nucleotides are denoted by the letters GC?

Answer 8

Guanine

Cytosine

Question 9

the A-T nucleotide bond has how many hydrogen bonds?

Answer 9

2

Question 10

A nitrogenous base combined with a five-carbon sugar is known as a:

Answer 10

Nucleoside

Question 11

What is the end product of purine catabolism in humans?

Answer 11

Uric Acid

Question 12

Enzymes which synthesise which pyramidine triphosphate are the target of chemotherapy drugs?

Answer 12

TTP

Thymine Triphosphate

Question 13

“The base is synthesised first, and the sugar added later” does this describe:

Purines

or

Pyramidines?

Answer 13

Pyramidines

Question 14

Which of the proteinacious channels of the mitochondrial membranes lie on the outer membrane?

(TIM & TOM)

Answer 14

TOM

Question 15

the G-C nucleotide bond has how many hydrogen bonds?

Answer 15

3

Question 16

What molecules are the prime donors of nitrogen in purine synthesis?

Answer 16

Amino Acids

Question 17

Xeroderma Pigmentosum is a rare autosomal recessive disease that is caused by abberant dimerisation of which nucleaic base?

Answer 17

Thymine

Question 18

Guanine and adenine are:

Purines

or

Pyramidine?

Answer 18

Purines

Question 19

What are the nucleotides denoted by the pair TA?

Answer 19

Adenine

Thymine

Question 20

Which circulating antioxidant is the end product of purine catabolism in humans?

Answer 20

Uric Acid

Question 21

The bonds between pairs of nucleotides in a complete DNA molecule are ________ ; the bonds between the deoxyribose molecules are Covalent Bonds.

Answer 21

Hydrogen bonds

Question 22

which electron transporting molecule is used for reductive biosynthesis of fatty acids?

Answer 22

NADP⁺ / NADPH

Question 23

what is the purpose of the TIM and TOM channels in the mitochondrial membranes?

Answer 23

Importation of cytosolic proteins to the mitochondria

Question 24

Thymine, Cytosine and Uracil are:

Purines

or

Pyramidine?

Answer 24

Pyramidines

Question 25

“The nucleotide is assembled on a ribose-5-P scaffold” does this describe:

Purines

or

Pyramidines?

Answer 25

Purines

Question 26

A nucleotide is a phosphorylated form of what molecule?

Answer 26

Nucleoside