nucleic acids

Question 1

bases in DNA

Answer 1

adenine - thymine
cytosine - guanine

Question 2

tRNA

Answer 2

transfers specific amino acids to ribosomes for protein synthesis

Question 3

what is ATP made up of?

Answer 3

• 3 phosphate groups
• ribose
• adenine

Question 4

describe structure and function of DNA

Answer 4

• 2 anti-parallel polynucleotide chains
• 2 hydrogen bonds between adenine and thymine, 3 hydrogen bonds between cytosine and guanine - allow genetic information to be passed from generation to generation without change
• long - can store a lot of genetic information
• sugar phosphate backbone - protects bases
• weak hydrogen bonds - easy separation for DNA replication

Question 5

what is a nucleotide made up of

Answer 5

• phosphate group
• pentose sugar (deoxyribose in DNA, oxyribose in RNA) - nitrogenous base

Question 6

mRNA

Answer 6

transfers genetic information from DNA to ribosomes

Question 7

function of ATP

Answer 7

• immediate source of energy (active transport, movement, endo/exocytosis
• small and soluble to be easily transported around cell
• Pi can be bonded to different compounds to make them more reactive

Question 8

how are polynucleotides formed?

Answer 8

• condensation reactions
• phosphodiester bond forms between phosphate of one nucleotide and the carbon 3 of another
• forms sugar-phosphate backbone

Question 9

describe semi conservative replication

Answer 9

1. double helix untwists
2. DNA helicase breaks hydrogen bonds between bases so 2 strands separate
3. both strands act as templates
4. free nucleotide bases hydrogen bond to exposed bases according to complementary base pair rule
5. DNA polymerase forms phosphodiester bonds to make sugar-phosphate backbone
6. each DNA molecule consists of 1 old strand and 1 new strand

Question 10

bases in RNA

Answer 10

adenine - uracil
cytosine - guanine

Question 11

rRNA

Answer 11

together with proteins makes up ribosomes