Translation The Details

Question 1

A (aminoacyl binding) site

Answer 1

Incoming tRNA carrying amino acid binds here on mRNA

Question 2

P (peptide binding) site

Answer 2

Site where amino acid chain is built

Question 3

E site

Answer 3

Where tRNA exits ribosome

Question 4

Initiation of translation

Answer 4

• > ribosomes recognize the 5’cap and the start codon

- >ribosomes reads mRNA in the 5’ to 3’ direction adding a new amino acid for each codon read

Question 5

Transfer RNA translation

Answer 5

tRNA delivers the correct amino acid to the protein building site on the ribosome

• tRNA resembles a 4 leaf clover
• third base in each codon is flexible (allows correct amino acid to be added despite mRNA errors

Question 6

Anticodon

Answer 6

The arm of the molecule recognizes the codon on mRNA

part of Transfer RNA

Question 7

Acceptor arm

Answer 7

Carries the corresponding amino acid

Part of transfer RNA

Every tRNA carries only one amino acid

Question 8

Elongation in transfer RNA

Answer 8

1. tRNA binds to A site
2. Peptidyl transferase cleaves the amino acid from the p site and bonds it to the amino acid on the A site
3. Ribosomes moves along the mRNA to the next codon, bringing the tRNA with the growing polypeptide to the P site and moving the empty tRNA to the E site
4. After the ribosome has moved over one codon the empty tRNA in the E site is released and cycle is ready again

Question 9

What is translation?

Answer 9

mRNA enters cytoplasm and is ready for translation into protein by the ribosomes

Question 10

Termination of translation

Answer 10

• ribosome reaches stop codon (does not code for amino acid)
• release factor= protein that helps ribosome to release polypeptide
• protein folds into 3-D area of cell where it is needed

Question 11

Modifications of translation

Answer 11

->Sugars and phosphates may be added to some amino acids
->some enzymes may cleave chain at specific spots
ex. Insulin
Preproinsulin / pro insulin / insulin