Translation

Question 1

Shine Dalgarno sequence (bacteria)

Answer 1

a consensus sequence on mRNA 5’ UTR that pairs with complement in small subunit

Question 2

Initiation Factor IF-3 (bacteria)

Answer 2

binds to small subunit and blocks large subunit for joining too early

Question 3

30s initiation complex (bacteria)

Answer 3

first complex formed in initiation. tRNA with IF-1, 2, and 3 and small subunit

Question 4

3 sites in the 70s complex ribosome (bacteria)

Answer 4

A site (charged tRNA enters), P site (amino acid chain grows), E site (tRNA exits)

Question 5

termination (bacteria)

Answer 5

stop codon is reached and no tRNA matches this codon. Release factors bind and the complex is dissociated, polypeptide released

Question 6

Initiation (eukaryotic)

Answer 6

5’ cap is recognized and binds to small subunit. Kozak sequence around start codon. More initiation factors than bacterial (keeps subunits apart, CBC checks for errors, bring first tRNA to start codon, CBC and poly-A tail enhance small subunit binding)

Question 7

Elongation (eukaryotic)

Answer 7

similar to bacterial but with more elongation factors. A, P, E sites

Question 8

Termination (eukaryotic)

Answer 8

stop codon encountered, no tRNA matches. release factors bind, complex dissociated, polypeptide released

Question 9

polyribosome

Answer 9

in both bacteria and eukaryotes molecules are translated simultaneously by multiple ribosomes

Question 10

What happens after the protein is made?

Answer 10

protein folding either spontaneously of by molecular chaperones. very important for function