Protein Metabolism II

Question 1

WHat are ribosomes?

Answer 1

noncovalent assemby of many proteins and few RNA molecules

Question 2

WHich are the size of bacteria and eukarotic ribsomes?

Answer 2

70s and 80S

Question 3

what are the size of bacteria and eu rRNAs?

Answer 3

16s in bacteria = 21 proteins 18s in eu = 33 proteins

Question 4

WHat are the 5 steps of proteins ysnthesis?

Answer 4

1. activation of AA
2. initiation of translation
3. Elongation
4. Termination and ribosome recycling
5. folding and post translational processing

Question 5

WHat binds to the A site of ribosomes?

Answer 5

aminoacyl site. it binds the aminoacyl-tRNAs

Question 6

What binds to the E site?

Answer 6

exit site. binds only uncharged tRNAs

Question 7

WHat binds to the P site of a ribosome?

Answer 7

Peptidyl site. it binds aminoacyl-tRNAs

Question 8

WHat are the common features of a TRNA?

Answer 8

single-stranded RNA (ssRNA) of 73-93 nucleotides in both bacteria and eukaryotes.
it has a cloverleaf strcuture 2d and twisted l shape 3-D
- most have G at the 5’ end
- all have CCA at the 3’ end
- have modifided bases

Question 9

What is the amino acid arm?

Answer 9

the amino acid arm is called that because there is an amino acid esterified via carbozyl group to the 2’ or 3’ OH group of A of CCA. all trnas. it includes the nucleotide and the phosphate

Question 10

what is the anticodon arm