Lecture 5 Dr. MacDonald

Question 1

Central Dogma:

Answer 1

DNA to RNA to Protein

Question 2

Clint’s Modified Central Dogma:

Answer 2

In Nucleus: DNA to hnRNA to Cytoplasm To mRNA to Protein

Question 3

Define: hnRNA

Answer 3

heterogeneous nuclear RNA - pre-mRNA

Question 4

Define: Sense Strand

Answer 4

The DNA that looks like the transcribed RNA

Question 5

Define: Antisense Strand

Answer 5

This DNA is what polymerase transcribes

Question 6

3 Major RNA Polymerases

Answer 6

I, II, and III

Question 7

RNA Pol I

Answer 7

Makes only Ribosomal RNA
18S and 28S
S stands for segmentation units

Question 8

RNA Pol II

Answer 8

makes hnRNA

Question 9

Whole ribosome S size?

Answer 9

80S

Question 10

What does rRNA not have?

Answer 10

A cap

Question 11

RNA Pol III

Answer 11

Makes tRNA and the 5S rRNA

Do not have caps

Question 12

RNAs made by RNA Pol I and RNA Pol III do not have 5’ caps; instead, what structure do those RNAs have at their 5’ ends?

Answer 12

3 phosphates on the first nucleotide

Question 13

What does dnaG do?

Answer 13

RNA primers for DNA replication (aka. Primase)

Question 14

Major Classes of Euk RNA Polymerases

Answer 14

RNA Pols I, II, and III

Question 15

Actinomycin D sensitivity:

Answer 15

RNA Pol I

Intercalates into DNA and spreads apart the DNA making it look non authentic to the replication machinery

Question 16

Alpha-amanitin sensitivity:

Answer 16

RNA pol II

Question 17

What are the four major mRNA processing events for Eukaryotic mRNAs?

Answer 17

5’ end capping, 3’ end polyadenylation, intron splicing, cap and internal nucleotide methylation

Question 18

Start Codon

Answer 18

AUG

Question 19

Stop Codons:

Answer 19

UAA, UAG, UGA

Question 20

5’ untranslated region

Answer 20

precedes the open reading frame (coding region)

Question 21

3’ untranslated region

Answer 21

sandwiched between the stop codon and poly A tail

Question 22

5’ Cap

Answer 22

is a methylated Guanine (me7G) + the fist 2 nucleotides + methylation of the two nucleotides

Question 23

5’ to 5’ triphosphate linkage

Answer 23

marker by which quality control recognizes capped mRNA

Question 24

3’ end polyadenylation

Answer 24

mRNA is cut and poly A tail is added

Question 25

Upstream sequence element

Answer 25

85% AAUAAA
12% AUUAAA
3% Other (As mostly and maybe U)

Question 26

Where the does upstream sequence element occur?

Answer 26

Approx 12-38 nt before the downstream segment element

Question 27

Downstream sequence element

Answer 27

much less conserved, approximately 12-24 nt following teh upstream event. will be chopped off and digested in the nucleus

Question 28

Poly(A) polymerase

Answer 28

Adds the poly A tail

Question 29

CPSF

Answer 29

major complex that recognizes the upstream sequence and downstream sequence and cleaves it

Question 30

CPSF-30 and WER33

Answer 30

specifically recognize the upstream sequence

Question 31

CatF

Answer 31

3 subunits, that act as a scaffold, with CstF-64 binds to the downstream site

Question 32

CPSF-73

Answer 32

cleaves the upstream and downstream regions apart

Question 33

Splicing

Answer 33

Intron removal

Question 34

Things to look for in intron:

Answer 34

look for GU dinucleotide at the beginning of an intron, and a AU dinucleotide at the end

Question 35

snRNP

Answer 35

Small nuclear ribonuclear protein

Question 36

GU binds to AC branch site and is spliced together

Answer 36

Lariat

Question 37

CTD

Answer 37

C-terminal domain