3.8

Question 1

What are the components of a nucleotide?

Answer 1

Pentose monosaccharide
Phosphate group
Nitrogenous base

Question 2

How are nucleotides linked together

Answer 2

Condensation reaction. Phosphate group on 5th carbon of sugar forms covalent bond w hydroxyl group on 3rd carbon of other nucleotide. Called phosphodiester bonds. Forms a sugar phosphate backbone.

Question 3

How are phosphodiester bonds broken

Answer 3

Hydrolysis

Question 4

What are the four bases in DNA

Answer 4

Adenine
Thymine
Guanine
Cytosine

Question 5

What are the smaller bases called and what bases are they?

Answer 5

Pyrimidines

Thymine cytosine

Question 6

What are the larger bases called and what bases are they?

Answer 6

Purines

Adenine guanine

Question 7

Differences between DNA and rna

Answer 7

Deoxyribose sugar 
DNA has thymine base 
Rna 
Ribose sugar
Uracil base

Question 8

What shape has DNA got and how?

Answer 8

Two strands of polynucleotides wound together in a double helix (antiparallel) held together by hydrogen bonds between bases.

Question 9

Base pairing rules

Answer 9

Adenine and thymine able to form 2 H bonds so only bind w each other

Cytosine and guanine able to form 3 H bonds so only bind w each other

Pyrimidine always binds w purine

Equal amounts of adenine and thymine and equal amounts of guanine and cytosine