Block 2

Question 1

Turning off expression without changing the code..

Answer 1

Epigenetics

Question 2

Transcription factors are…

Answer 2

Proteins

Question 3

Epigenetics

Answer 3

A change in the expression of a gene that changes the phenotype without permanently changing the gene itself. Typically involving changes in chromatin structure.

Question 4

Euchromatin

Answer 4

loose and can actively transcribe

Question 5

Heterochromatin

Answer 5

Dense packing of DNA, which makes it less accessible

Question 6

HAT

Answer 6

histone acetyl transferase –> euchromatin

Question 7

HDAC

Answer 7

histone deacetylase –> heterochromatin

Question 8

Cis

Answer 8

Elements of DNA that are inactive without a protein bound. Do not have a fixed location, could be a promotor, enhancer, silencer.

Question 9

Trans

Answer 9

Proteins that bind to cis-acting sequences. They can activate or repress transcription.

Question 10

HIF-1a is hydroxylated the degraded by proteosomes when?

Answer 10

High oxygen

Question 11

HIF-1a stabilized, moves to the nucleus and dimerizes with HIF-1B to activate multiple genes that enhance oxygen delivery to tissues and/ or energy supply via glycolysis when?

Answer 11

Low/ no oxygen

Question 12

In a human cell and under normal atmospheric conditions, certain amino acids found on the HIF-1a peptide will hydroxylate by what enzyme?

Answer 12

Prolylhydroxylase complex

Question 13

What is the nucleosome core composed of?

Answer 13

2 molecules of H2A, H2B, H3 and H4

Question 14

Increases Gene Expression

Answer 14

enhancer

Question 15

Why is DNA methylated in eukaryotes?

Answer 15

To form heterochromatin and keep genes in the region turned off

Question 16

What neutralizes the charges on histones and loosens up interactions between histones and DNA?

Answer 16

Acetylation

Question 17

Deacetylation

Answer 17

HDACs

Question 18

Acetylation

Answer 18

HATS (loosen histones)

Question 19

Methylation

Answer 19

add a CH3

Question 20

Dnmt3

Answer 20

responsible for de novo methylation of DNA

Question 21

Dnmt1

Answer 21

maintenance

Question 22

MeCP2

Answer 22

binding protein

Question 23

mSin3A

Answer 23

helps HDACs

Question 24

GR forms a dimer with?

Answer 24

Cortisol

Question 25

What influences differential splicing?

Answer 25

Proteins expressed differently in cells

Question 26

What happens to mRNA molecules with long poly-A tails?

Answer 26

Translated in the cytoplasm

Question 27

What happens with an mRNA molecule has only part of its poly-A tail?

Answer 27

Remains untranslated

Question 28

Unfertilized oocyte

Answer 28

5' guanosine is not methylated and cannot be translated

Question 29

Fertilized Oocyte

Answer 29

5' guanosine has 7- methyl and can be translated

Question 30

Oogenesis- Oocyte growth: Oocyte cleavage:

Answer 30

Oocyte growth: long poly-A tails and immediately translated | Oocyte cleavage: poly-As clipped off, translation blocked

Question 31

After Oocyte fertilization translation stops because?

Answer 31

Poly-A tails are removed

Question 32

After Oocyte fertilization translation begins because?

Answer 32

Long poly-A tails

Question 33

What does CPEB do?

Answer 33

Recruits maskin

Question 34

What does Progesterone do to CPEB?

Answer 34

Activates protein kinase that phosphorylates CPEB and maskin is released and translation can proceed

Question 35

What binds to initiate translation for interfering proteins?

Answer 35

PABP

Question 36

What is the function of Puf proteins when bound?

Answer 36

Inhibit translation (inhibit ribosome binding and inhibit a long poly-a tail)

Question 37

When GF is inactive it is bound to?

Answer 37

heat shock proteins

Question 38

Unfertilized eggs are hidden by ? and are not translated

Answer 38

RNPs

Question 39

At fertilization what releases the masking proteins to allow for translation?

Answer 39

ionic changes

Question 40

What is the function of IRES in eukaryotic mRNA?

Answer 40

It allows the translation of uncapped mRNA

Question 41

What does Bicoid protein bind to that inhibits translation?

Answer 41

Caudal mRNA

Question 42

Why is caudal mRNA less inhibited at the posterior end of the fruitfully?

Answer 42

Because there is less Bicoid protein

Question 43

Where is the most abundant spot of Bicoid protein in a fruitfully?

Answer 43

Anterior

Question 44

Function of Bicoid protein?

Answer 44

Inhibit translation

Question 45

Low iron

Answer 45

Transferrin receptor on | Ferritin expression off

Question 46

High iron

Answer 46

Transferrin receptor off | Ferritin expression on

Question 47

What is differential splicing?

Answer 47

RNA processing of PRIMARY transcripts which lead to the production of mRNAs which encode for DIFFERENT proteins. Exons are spliced in certain ways that yield ALTERNATE mRNA transcripts.