Nucleotides

Question 1

Describe the 3 parts of a nucleotide

Answer 1

Phosphate group
Pentose sugar
Nitrogenous base

Question 2

What elements are found in nucleotides?

Answer 2

Carbon
Oxygen
hydrogen
phosphorous
nitrogen

Question 3

What is the structure of a purine?

Answer 3

Have double rings of carbon and nitrogen atoms

Question 4

What is the structure of a pyramadine?

Answer 4

Have a single ring of carbon and nitrogen atoms

Question 5

Name all the purines

Answer 5

Adenine

Guanine

Question 6

Name all the pyramadines

Answer 6

Thymine
Cytosine
Uracil

Question 7

What bonds form between nucleotides?

Answer 7

Phosphodiester bonds

Question 8

What reaction forms a phosphodiester bond?

Answer 8

Condensation reaction

Question 9

What is the backbone of DNA and RNA known as?

Answer 9

Sugar-phosphate backbone

Question 10

How many hydrogen bonds form between adenine and thymine

Answer 10

2

Question 11

How many hydrogen bonds form between guanine and cytosine?

Answer 11

3

Question 12

What are two adaptations that make DNA well suited for its function?

Answer 12

Sugar-phosphate backbone makes molecule more stable
Double helix makes molecule more compact
2 strands can seperate for replication

Question 13

What does generate code mean?

Answer 13

One amino acid can be coded for by more than one codon

Question 14

What are introns?

Answer 14

Non coding regions of a gene, doesn’t code for an amino acid

Question 15

What are exons?

Answer 15

Portion of a gene that codes for an amino acid

Question 16

Name 3 reasons why ATP is a useful

Answer 16

Releases energy in small amounts
Releasaes energy quickly
Can phosphorilate other molecules-makes them more reactive
Easily re-synthesised

Question 17

Describe the structure of ATP

Answer 17

3 phosphate groups
Ribose sugar
Adenosine base

Question 18

What reaction is used to make ADP into ATP?

Answer 18

Condensation reaction

Question 19

Name the steps in extracting DNA from cells

Answer 19

1) Break open cells (e.g blend strawberry cells)
2) mix detergent, sodium chloride and distileld water. This will dissolve membranes and clump them together
3) mix mashed cells with solution
4) filter mixture to remove cell debris and whole cells
5) slowly pour ethanol onto filtered solution to form a layer on top
6) wait around 10 mins
7) DNA will form white precipitate between layers
8) use tweezers to extract DNA or centrifuge to form pellets