translation

Question 1

what is a codon

Answer 1

a sequence of 3 bases which codes for one amino acid

Question 2

what are anticodons and what molecule holds them

Answer 2

a sequence of 3 bases on a trna
they are complimentary to a specific codon on mrna

Question 3

what components of a trna molecule make it so specific

Answer 3

they hold specific anticodons which are complimentary to a specific codon
they also carry a specific amino acid

Question 4

briefly describe the 4 protein structures

Answer 4

primary- amino acid sequence

secondary- alpha helix or beta pleated sheet

tertiary- folded 3d shape

quaternary- combines with other polypeptides

Question 5

what bonds bind a trna and mrna

Answer 5

temporary hydrogen bonds

Question 6

describe the steps of translation

Answer 6

1- mrna binds to the centre of ribosome

2- trna anticodon is complimentary to a codon on an mrna and they bind together through temporary hydrogen bonds

3-another trna with specific amino acid will then bind to the next codon

4- the 1st amino acid binds to the 2nd amino acid by a peptide bond via peptidyl transferase, which joins amino acids together

5- ribosome moves along rna whilst trna joins and leaves and an amino acid chain is formed

6- the ribosome will reach a stop codon, knowing when to stop binding to trna and the polypeptide will be released

Question 7

what does peptidyl transferase do

Answer 7

enzyme at the ribosome which joins two amino acids together by forming peptide bonds, it continues to join amino acids until finished

Question 8

what bond is used to join amino acids

Answer 8

peptide

Question 9

how many nucleotides code for one amino acid

Answer 9

3 nucleotides code for 1 amino acid

Question 10

when does the process of translation know when to stop

Answer 10

when the ribosome reaches a stop codon, the polypeptide is released

Question 11

what bond is formed between amino acids on trna

Answer 11

peptide bonds

Question 12

define translation

Answer 12

forming of a protein at ribosomes by joining amino acids in a particular sequence according to coded instructions from dna carried by mrna

Question 13

name the pentose sugars in dna and rna

Answer 13

dna- deoxyribose

rna- ribose

Question 14

what reactions join and break down polynucleotides

Answer 14

condenstation and removal of water- joins

hydrolysis and addition of water breaks down

Question 15

describe the structure of a purine

Answer 15

adenine guanine

two ring molecules

Question 16

describe pyrimidine structure

Answer 16

uracil
thymine
cytosine

one ringed