Protein Synthesis (Page 2 of 4) in pdf

Protein Synthesis Page 2

SICM Tuition

Biology AS

In the cytoplasm

the spliced mRNA then moves out of the nucleus via a nuclear pore

the mRNA goes to a ribosome

the first triplet code to be read is AUG. This codes for the start codon

(methionine)

the codes on the mRNA are called codons

the ribosome can hold 2 triplet codes together…

the mRNA enters the ribosome and as it does so, tRNA (transfer RNA) comes

and joins complementary bases to it. The complementary triplet bases on the tRNA

are called anti-codons.

a tRNA molecule is made up of three bases at one end and an amino acid at the

other end

many different tRNA molecules are present in the cytoplasm for this to occur

this continues and as it does, the amino acids line up (2 at a time – as each

ribosome can hold 2 triple codes) and bond together by peptide bonds catalysed

by the enzyme peptidyl transferase.

This continues until a stop codon is reached. The stop codons do not code for any

amino acid, but stop the translation.

many amino acids make up a protein

the mRNA that moves along can simply be re-used again and again

Translation animation

Highly recommended….very nice way to put it all together

Page 6

Protein Synthesis Page 2