Eukaryotic Gene Regulation Flashcards Preview

EOM Test 2 > Eukaryotic Gene Regulation > Flashcards

Flashcards in Eukaryotic Gene Regulation Deck (22)
Loading flashcards...
1
Q

What are three ways chromosomal regions can act as control points?

A
  • Inactivated during development
  • Activated by translocation
  • Gene deletion
2
Q

What is an example of chromosomal inactivation?

A

X chromosomes in female

3
Q

What is an example of translocation as regulation?

A

Variable regions of antibody molecules

4
Q

What is an example of chromosomal material being lost?

A

Human red blood cell

5
Q

What is Gene reiteration?

A

The presence of many identical genes

Allows transcripts to be made at a high rate

6
Q

How can the initiation of transcription act as a control point?

A

Through the use of specific transcription factors that are regulated

7
Q

What are four ways mRNA can be used as a point of regulation?

A
  • alternative splicing
  • transportation from the nucleus
  • rate of degradation
  • masking to an “inactive” form
8
Q

How does histone acetylation affect gene expression?

A

Acetylated = favors gene expression

Deacetylation = inactive chromatin

9
Q

What is the role of scaffolding proteins in gene expression?

A

Condense regions of the chromatin (inactive)

10
Q

How does methylation affect gene expression?

A

DNA methylation favors inactive chromtin

11
Q

What is the role of promoters?

A

Bind general transcription factors

12
Q

What is the role of enhancers?

A

Bind specific transcription factors

Act in a tissue-specific manner

‘Target for steroid hormones

13
Q

What is the difference between trans regulators and cis regulators?

A

Trans regulators – proteins that act on specific DNA sequences

Cis regulators – elements within the DNA that serve regulatory functions (e.g. promoter, enhancer)

14
Q

What are four ways of activating transcription factors?

A
  • Synthesis
  • Ligand binding
  • phosphorylation
  • addition of second subunit
15
Q

How do steroid hormones activate transcription factors?

A

Through ligand binding

16
Q

What are three common structures of DNA-binding proteins?

A
  • Zinc finger
  • Helix-Turn-Helix
  • Leucine Zipper
17
Q

Describe Ferritin and Transferrin Receptor translation in low iron.

A

A protein is active and binds the mRNA of ferritin and transferrin, this promotes the translation of the receptor and represses ferritin.

In high iron, the protein doesn’t bind and the opposite happens

18
Q

What is RNA interference?

A

Small RNA molecules that bind to the 3’ untranslated region of an mRNA molecule to interfere with translation

19
Q

What is the function of microRNA?

A

An imperfect match for mRNA, binds and inhibits translation

20
Q

What is the function of short interfering RNA?

A

An exact match for the 3’ end of mRNA, binds and causes mRNA degredation due to the presence of double stranded RNA

21
Q

What is the cause of Prader-Willi Syndrome?

A

Deletion on chromosome 15 inherited by the father

The maternal copy is methylated at this region, and therefore inactive.

Hypogonadism, small hands and feet, obesity, mental retardation

22
Q

What is the cause of Angelman syndrome?

A

Deletion on chromosome 15 inherited by the mother

The paternal copy is methylated at this region, and therefore inactive

seizures, ataxic gait, behavior disorders, mental retardation