biochem 7A - protein synthesis

Question 1

amino acid sequence can be determined by

Answer 1

mass spec

Question 2

high performance liquid chromatography (HPLC)

Answer 2

separate the components of a mixture via column

Question 3

x-ray crystallography and nuclear magnetic resonance

Answer 3

determine 3D structure

Question 4

codon nucleotide sequences are always written in what direction

Answer 4

5’-3’

Question 5

start codon

Answer 5

aug

Question 6

stop codons

Answer 6

UAG, UAA, UGA,
(u are gross, u are annoying, u go away)

Question 7

substituion mutation -transition and transversion

Answer 7

transition - replace purine w purine vice versa
transversion - replace puryin with a pyrimidine vice versa

Question 8

missense mutation

Answer 8

codon containing the changed base may code for a different aa

Question 9

nonsense mutation

Answer 9

codon containing the changed base may become a terminal codon

Question 10

tRNA function and form

Answer 10

-transfer aa
-each tRNA has an attachment site for a specific AA at its 3’ end
-carboxylic group of AA binds OH of ribose at 3’ end
-when a tRNA has a covalently attached aa, it is said to be charged, aa is said to be activated
-anticodon on tRNA bind mRNA codon

Question 11

aminoacyl-tRNA synthetases function

Answer 11

catalyzes attachment of amino acid to tRNA

Question 12

ribosome function of small and large subunit

Answer 12

small subunit - binds mRNA and is responsible for the accuracy of translation by ensuring correct base-pairing between codon and anticodon

large subunit - catalyzes peptide bond formation

organelle where protein synthesis occurs
consists of protein and rRNA

Question 13

what type of binding occurs between codon and anticodon

Answer 13

antiparallel binding

Question 14

mRNA codon read what direction

Answer 14

5’-3’

Question 15

anitocodn orientation

Answer 15

3’-5’

Question 16

nucleotide sequences are always assumed to be written what direction

Answer 16

5’-3’

Question 17

wobble hypothesis

Answer 17

tRNA can recognize more than one codon for a specific aa

first base of the anticodon 5’ is less striegen than the other two

Question 18

peptidyltransferase

Answer 18

catalyzes peptide bond formation

Question 19

co and post translational modification of polypeptide chains

Answer 19

-phosphorylation
-glycosylation
-hydroxylation
-carboxylation

Question 20

ubiquitination

Answer 20

-proteins that are defective can be degraded
-attachment of chains of small proteins called ubiquitin

Question 21

what cellular component in the cytosol degrades in ubiquitination

Answer 21

proteasome