DNA Structure

Question 1

DNA stands for?

Answer 1

Deoxy ribonucleic acid

Question 2

RNA stands for?

Answer 2

Ribose nucleic acid

Question 3

Watson and Crick’s model of DNA double helix consists of two complementary and parallel strands. T/F?

Answer 3

False. 2 complementary and 2 ANTIparallel strands

Question 4

Nucleotide = nucleoside + ____

Answer 4

Phosphate

Question 5

Base + ___ = nucleoside

Answer 5

Sugar

Question 6

What is the chemical basis of base pairing in the DNA double helix?

Answer 6

Hydrogen bonds

Question 7

What are purines?

Answer 7

Adenine and Guanine, DOUBLE RING

Question 8

What are pyrimidines?

Answer 8

Cytosine, Thymine, and Uracil, SINGLE RING

Question 9

The regions where DNA binding proteins make direct contact w nucleotides in a double helix?

Answer 9

Major and minor grooves

Question 10

What is supercoiling?

Answer 10

A result of untwisting or over-twisting the double helix. Relieves the stress the tis introduced as a result of over or under twisting DNA.

Question 11

How is supercoiling regulated?

Answer 11

Enzymes called topoisomerases

Question 12

What is real DNA?

Answer 12

B-form, more hydrated. left-handed. MOST PREVALENT