430

Question 1

Sense RNA

Answer 1

Codes for protein

Question 2

PTGS

Answer 2

Degradation of mRNA post transcription

Question 3

Antisense RNA

Answer 3

Complementary

Question 4

How does dsRNA affect protein production?

Answer 4

Anti/sense cancel out

Question 5

RNA silencing

Answer 5

Process where small RNAs, usually working with protein machinery, inhibit gene expression.

Question 6

What uses dsRNA?

Answer 6

Invertebrates

Question 7

Can small dsRNAs inhibit protein synthesis? Globally? (In vertebrates?)

Answer 7

Yes, no

Question 8

MicroRNAs

Answer 8

Extremely small RNAs that regulate the expression of a specific mRNA.

Question 9

How are MicroRNAs synthesized?

Answer 9

RNA polymerase II, primary transcript

Question 10

MicroRNA sequence in animal cell

Answer 10

Partially complementary to 3’ UTR of mRNA target

Question 11

What processes are micrornas used in?

Answer 11

nervous system patterning, cell reproduction/death, cell differentiation

Question 11

What are piwi interacting RNAs?

Answer 11

Suppress movement of transposable RNAs

Question 11

Why are piwi interacting RNAs so important?

Answer 11

Prevent translocation of genes that would cause genetic disorders

Question 12

Piwi rna structure

Answer 12

Longer, structure can vary a lot even in same gene

Question 13

How are histones modified

Answer 13

Cells use enzymes to add/subtract chemical groups to histone residues

Question 14

Histone code

Answer 14

Functino of chromatin follows the modifications it has

Question 15

What AA are methyl groups added to?

Answer 15

Lysine or arginine,

Question 16

What AA are acetyl groups added to?

Answer 16

Lysine

Question 17

What are phosphate groups added to

Answer 17

Serine

Question 18

What do modified residues do?

Answer 18

Let nonhistone proteins bind to histones

Question 19

What needs to happen to an mRNA so it can function?

Answer 19

5’ cap, 3’ poly A tail, intron removal (can happen in multiple ways in the same gene, allowing for multiple proteins in one gene

Question 20

How are exons spared?

Answer 20

If they’re weak they may not be removed under certain conditions

Question 21

What is RNA editing?

Answer 21

A means of gene regulation where nucleotides are converted to other nucleotides post translation

Question 22

What are some mechanisms that regulate gene expression

Answer 22

1. Localizing mRNAs to where they’re needed 2. Controlling levels of translation 3. 1/2 life of mRNA

Question 23

What happens when a human cell is subjected to stress?

Answer 23

Protein kinase is activated, phosphorylates eIF2, blocks further synthesis. eIF2 can't exchange GDP for GTP, so no futher translation

Question 24

What does mRNAs leaving cytoplasm do?

Answer 24

Lets them travel to new cells- can determine where structures form

Question 25

What determines where mRNAs go?

Answer 25

e' UTR

Question 26

How is poly a tail (and therefore mRNA) degraded?

Answer 26

Deadenylase breaks it down- becomes unstable with ~30 A left

Question 27

What happens to 5' cap after poly a is degraded?

Answer 27

P bodies degrade it because poly a tail protects it

Question 28

What factors contribute to mRNA stability?

Answer 28

UTR sequence, microRNA and protein activity

Question 29

How do MicroRNAs silence genes?

Answer 29

Deadenylating mRNAs, interfering with translation, blocking translation elongation, recruiting proteases to degrade proteins

Question 30

The higher the mRNA levels

Answer 30

The lower the complementary mRNA levels