Translation - the genetic code

Question 1

genetic code description

Answer 1

non overlapping
degenerate
triplet code

Question 2

frameshift mutations

Answer 2

insertions/deletions in the code

Question 3

how does mRNA recognise the amino acids

Answer 3

• binds molecules of tRNA
• each tRNA contains an anticodon
  which is complementary to mRNA codon

Question 4

synonymous

Answer 4

codons coding for the same amino acid

Question 5

degenerate code meaning

Answer 5

3 AA are specified by 6 diff codons
multiple codes have the same meaning

Question 6

variant arm

Answer 6

the site of variability
-3 to 21 nucleotides

Question 7

what does aminoacyl-tRNA synthetase do

Answer 7

selects the correct amino acid for covalent attachment to the correct tRNA

Question 8

how is aminoacylation catalysed

Answer 8

by 1 enzyme in 2 steps
1. the AA is activated and forms an aminoacyl-adenylate
2. it reacts tRNA to form aa-tRNA

Question 9

amino acid + tRNA + ATP ->

Answer 9

aminoacyl-tRNA + AMP + PP

Question 10

what happens as a result of “wobble”

Answer 10

many tRNAs may bind to more than 1 codon

Question 11

what is wobble

Answer 11

the non-standard base pairing that can occur between the third position of an mRNA codon and the first position of a tRNA anticodon during translation

Question 12

what is the site of protein synthesis

Answer 12

the ribosomes
mRNA is translated at this site with the hero if an adaptor molecule tRNA

Question 13

how is mRNA deciphered

Answer 13

in codons of 3 nucleotides