Exam 4

Question 1

DNA polymerase iii

Answer 1

Extends on the 3’ end of primers to make daughter strand

Question 2

DNA polymerase i

Answer 2

Replaces rna primers with dna nucleotides

Question 3

Ligand

Answer 3

Links dna fragments together with covalent bonds (phosphdiester)

Question 4

Limitations to the dna polymerases

Answer 4

Can only add to the 3’ end
Need a primer, can not make their own dna strand

Question 5

Nuclei acids are made up of

Answer 5

Phosphate backbone, sugar (deoxy or ribose), and a nitrogenous base

Question 6

The only purines?

Answer 6

Adenine and guanine

Question 7

Transcription: Initiation

Answer 7

In prokaryotes rna polymerase can directly bind to TATA box, in eukaryotes it needs Basal transcription factors

Question 8

Start and stop codons

Answer 8

Start: AUG
Stop: UAA, UAG, UGA

Question 9

TRNA

Answer 9

Each amino acid (20) has a different tRNA and enzyme associated with it

During transcription it binds to the proper mRNA codon
Codons represent a code, more than one codon represents the same amino acid

Question 10

Inside the ribosome: initiation

Answer 10

Starts when the ribosome subunit binds to mRNA near the 5’ end
Prokaryotes: sequences recognized is the Shine Delgado, 8 bases up of AUG
Eukaryotes: first 5’ AUG
MET tRNA is in the P site

Question 11

Elongation

Answer 11

A tRNA enters the A site, the peptide in the P site is attached to the new amino acid in the A site, as this happens the ribosome is sliding down, shifting P to E and A to P

Question 12

Why can multiple codons interact with the same tRNA

Answer 12

The parities is imperfect, tRNA is curved, creating a wobble that allows for this to happen