DNA and Nucleotide propeties

Question 1

The Phosphate bonds to what carbon

Answer 1

5’ Carbon

Question 2

The base bonds to what carbon

Answer 2

1’ Carbon

Question 3

Deoxyribose and Ribose differ in the fact that they either have an OH or H group on what carbon

Answer 3

2’ Carbon

Question 4

The OH group that forms the ester linkage is on what carbon

Answer 4

3’

Question 5

Are pentose rings planar

Answer 5

no, they exist in pucker conformations

Question 6

Nucleotides absorb UV light strongly at what wavelength

Answer 6

260nm due to the resonance

Question 7

When a nucleoside forms what is released

Answer 7

A water molecule

Question 8

Phosphates have a low pKa meaning that they are

Answer 8

deprontonated at physiological pH and .’. negatively charged

Question 9

The primary structure of DNA is

Answer 9

the list of nucleotides

Question 10

The secondary structure of DNA is

Answer 10

the two antiparallel complementary strands joint by hydrogen bonds

Question 11

How many H-Bonds form between Adenines and Thymins

Answer 11

2 H-Bonds

Question 12

How many H-Bonds form between Cytosine and Guanoine

Answer 12

3 H-Bonds

Question 13

Double bonds in the bases make the pyrimidines…………… and the purines …………………

Answer 13

Pyrimidines = Planar
Purines = Nearly planar

Question 14

Why must nucleotides be planar?

Answer 14

It allows bases to stack more closely together and therefore decreases their interaction with water and thus stabilizing the structure of DNA

Question 15

DNA is a ………. handed helix with a ……….. and ………… groove

Answer 15

right handed helix with a major and minor groove

Question 16

In the watson-crick model, how many nucleotides are in one complete turn

Answer 16

10 nucleotides

Question 17

Single stranded DNA absorbs more light than double stranded DNA. True or False?

Answer 17

True

Question 18

What is the Tm

Answer 18

the temperature at which the DNA has reached half it’s total maximum denaturation

Question 19

As the number of CG pairings increase, so does the…….

Answer 19

Tm

Question 20

An increase in [salt] will …………. the DNA molecule because the cations will interact with the …………..

Answer 20

Stabilise the DNA

Interact with phosphates

Question 21

Changes in pH affect the protonisation of molecules, therefore a change in pH will ………… the ………….. bonds between bases

Answer 21

Distrupt the H-Bonds

Question 22

A region upstream (or to the 5’ end) from a gene is called a ……….. region

Answer 22

Promoter

Question 23

An area downstream (or to the 3’ end) from a gene functions to ……………. transcription

Answer 23

Terminate

Question 24

New nucleotides are added to the …… end of the existing chain

Answer 24

3’ end

Question 25

DNA replication requires:

Answer 25

A template strand A primer dNTPs DNA polymerase

Question 26

Each replicating DNA molecules has a .................. with the .............strand growing into it and the ..................... strand growing away from it

Answer 26

replication fork with a leading strand growing into it and a lagging strand growing away from it

Question 27

Lagging strand requires ................. to continue synthesis

Answer 27

okazaki fragments