ex17

Question 1

What is transcriptional regulation?

Answer 1

The control of transcription initiation through transcription factors binding to promoters or enhancers.

Question 2

What is the role of epigenetic modifications in gene expression?

Answer 2

They regulate gene accessibility by altering chromatin structure through DNA methylation or histone modifications.

Question 3

What is chromatin remodeling?

Answer 3

The repositioning or removal of nucleosomes by complexes like SWI/SNF to expose DNA for transcription.

Question 4

What is RNA processing?

Answer 4

The modification of pre-mRNA through splicing, capping, and polyadenylation to create mature and functional mRNA.

Question 5

How does RNA stability affect gene expression?

Answer 5

RNA-binding proteins and microRNAs regulate mRNA degradation or stability, determining how long it is available for translation.

Question 6

What is translational control?

Answer 6

The regulation of protein synthesis by influencing ribosome assembly or translation initiation, often through small RNAs or regulatory proteins.

Question 7

What are post-translational modifications (PTMs)?

Answer 7

Chemical changes to proteins, like phosphorylation or ubiquitination, that affect protein activity, localization, or stability.

Question 8

What is a transcription circuit?

Answer 8

A network of transcription factors and genes they regulate, controlling cellular responses and behaviors.

Question 9

What is a feedforward loop in a transcription circuit?

Answer 9

A motif where one transcription factor regulates another, and both target the same gene, creating robust or delayed responses.

Question 10

What is positive feedback in gene regulation?

Answer 10

A mechanism where a gene product activates its own production, stabilizing gene expression states like differentiation.

Question 11

What is negative feedback in gene regulation?

Answer 11

A loop where a gene product inhibits its own production, maintaining homeostasis or stabilizing fluctuations.

Question 12

What is a toggle switch in transcription circuits?

Answer 12

A bistable system where two genes mutually repress each other, enabling binary decisions like differentiation or apoptosis.

Question 13

What are transcription factors?

Answer 13

Proteins that bind to specific DNA sequences to regulate the initiation of transcription by RNA polymerase.

Question 14

What is DNA methylation?

Answer 14

The addition of methyl groups to cytosines in CpG islands, typically repressing gene expression by compacting chromatin.

Question 15

What are chromatin remodelers?

Answer 15

Protein complexes like SWI/SNF that reposition nucleosomes to make DNA accessible for transcription.

Question 16

What is alternative splicing?

Answer 16

The process of generating different mRNA variants by joining exons in different combinations.

Question 17

What is the role of microRNAs in gene expression?

Answer 17

MicroRNAs bind target mRNA to block translation or promote degradation, regulating gene expression post-transcriptionally.

Question 18

What is eIF2 phosphorylation?

Answer 18

A stress response mechanism that inhibits translation initiation to conserve cellular resources.

Question 19

What is ubiquitination?

Answer 19

The attachment of ubiquitin to a protein, marking it for degradation by the proteasome.

Question 20

What are histone modifiers?

Answer 20

Enzymes like HATs and HDACs that regulate gene expression by altering histone structure.

Question 21

What are DNA methyltransferases (DNMTs)?

Answer 21

Enzymes that add methyl groups to DNA, often silencing gene expression.

Question 22

What are RNA-binding proteins (RBPs)?

Answer 22

Proteins that control RNA splicing, localization, stability, and translation.

Question 23

List the 7 common ways to control gene expression.

Answer 23

1. Transcriptional Regulation. 2. Epigenetic Modifications. 3. Chromatin Remodeling. 4. RNA Processing. 5. RNA Stability. 6. Translational Control. 7. Post-translational Modifications.

Question 24

What is a feedforward loop?

Answer 24

A motif where a transcription factor regulates another transcription factor, and both control the same gene, enabling robust or delayed responses.

Question 25

What is positive feedback?

Answer 25

A feedback loop where a gene product enhances its own expression, stabilizing gene expression states.

Question 26

What is negative feedback?

Answer 26

A regulatory loop where a gene product inhibits its own expression, maintaining stability and homeostasis.

Question 27

What is a toggle switch?

Answer 27

A bistable circuit where two genes mutually repress each other, enabling a switch between two distinct states.

Question 28

Name the 4 common network motifs.

Answer 28

1. Feedforward Loop. 2. Positive Feedback. 3. Negative Feedback. 4. Toggle Switch.

Question 29

What is a G-protein Coupled Receptor (GPCR)?

Answer 29

A seven-transmembrane domain protein that activates intracellular signaling cascades via G-proteins (e.g., adrenaline signaling).

Question 30

What is an integrin?

Answer 30

A transmembrane receptor that links the extracellular matrix to the cytoskeleton, essential for cell adhesion and signaling.

Question 31

What is the retinoblastoma protein (Rb)?

Answer 31

A tumor suppressor that regulates the G1/S cell cycle transition by inhibiting E2F transcription factors.

Question 32

What is an egg polarity gene?

Answer 32

A gene that establishes body axes, such as anterior-posterior or dorsal-ventral, during development (e.g., bicoid in Drosophila).

Question 33

What is a morphogen?

Answer 33

A diffusible molecule that forms a concentration gradient to specify cell fate (e.g., Sonic Hedgehog in limb development).