2.1.3

Question 1

what elements do nucleic acids contain

Answer 1

carbon hydrogen oxygen nitrogen phosphorus

Question 2

what is nucleotide made up of

Answer 2

pentose monosaccharide
phosphate group ( -PO4 2-)
nitrogenous base

Question 3

what’s the polymer or nucleotides and how are they formed

Answer 3

polynucleotide and condensation reaction

Question 4

where does each nucleotide form phosphodiester bond

Answer 4

5’ (fifth carbon on pentose sugar
covalent bond with
hydroxyl group on 3’ of pentose sugar adjacent

Question 5

which bases are pyrimidines

Answer 5

Cytosine and thymine

Question 6

which bases are purines

Answer 6

adenine and guanine

Question 7

structural difference between deoxyribose sugar and ribose

Answer 7

H instead of OH on 2’

Question 8

cytosine forms how many hydrogen bones with

Answer 8

three with guanine

Question 9

how are polynucleotides arranged in double helix

Answer 9

antiparallel

Question 10

why does small pyrimidine base binds to large purine base

Answer 10

maintain constant distance between DNA backbones

Question 11

complementary base pairing means that DNA has equal

Answer 11

A and T
and
C and G

Question 12

a single gene is transcribed into a

Answer 12

mRNA molecule

Question 13

what happens to RNA molecules after protein synthesis

Answer 13

phosphodiester bonds hydrolysed and RNA nucleotides released and reused

Question 14

explain semi conservative replication

Answer 14

double helix DNA unwinds and seperate into two strands
free DNA nucleotides pair with bases hydrogen bonds form between them and phosphodiester bonds between new nucleotides

Question 15

what enzyme travels along DNA backbone catalysing reactions that break the hydrogen bonds

Answer 15

DNA helicase

Question 16

what does DNA polymerase do

Answer 16

catalyses formation of phosphodiester bonds between new nucleotides

Question 17

what is a mutation

Answer 17

change in the sequence of bases

Question 18

each codon codes for

Answer 18

an amino acid (3 bases)

Question 19

thé section of DNA that contains complete sequence of bases for a protein is a

Answer 19

gene

Question 20

why is the code known as degenerate

Answer 20

multiple codons code for same amino acids

Question 21

in transcription wnat enzyme unwinds the section of DNA that contains the gene

Answer 21

DNA helicase

Question 22

what is the name of the strand of DNA which contains the code for the protein to be synthesised

Answer 22

sense strand
5’ to 3’

Question 23

the antisense strand is the

Answer 23

template strand

Question 24

what enzyme forms the phosphodiester bonds between the RNA nucleotides

Answer 24

RNA polymerase

Question 25

explain translation

Answer 25

mRNA binds to small subunit of ribosome at its start codon a tRNA with anticodon binds to mRNA start codon another tRNA binds to next codon on mRNA two tRNA can be bound at same time formation of peptide bond catalysed by peptidyl transferase

Question 26

an ATP molecule is composed of

Answer 26

nitrogenous base, pentode sugar and three phosphate groups

Question 27

difference between DNA AND ATP

Answer 27

ATP base is always adenine and three phosphate groups instead of one sugar is ribose

Question 28

ATP + H2O result in

Answer 28

ADP + Pi(inorganic phosphate) + energy

Question 29

what is the process of reattaching a phosphate group to an ADP molecule

Answer 29

phosphorylation condensation reaction as water is removed

Question 30

why is ATP a good immediate energy store

Answer 30

ATP is instable ATP rapidly reformed by phosphorylation of ADP this happens constantly so cells do not have to have large store

Question 31

ATP properties and how these link to function

Answer 31

small so easily moves in and out of cells water soluble so energy requiring processes can happen in aqueous environments bonds between phosphates intermediate energy: have enough energy to be useful not too much so energy isn’t wasted as heat release energy in small quantities easily regenerated(recharged with energy)