Gene Regulation- Lecture 8/20/21

Question 1

Housekeeping genes

Answer 1

Genes presents in almost every cell, provide basic cell function ex: histones or GAPDH

Question 2

Nucleosome

Answer 2

The unit of DNA (~146 bp) wrapped around a histone octomer

Question 3

Histone octomer

Answer 3

2 each of histone 2A, 2B, 3, and 4

Question 4

Heterochromatin

Answer 4

Transcriptionally inactive and not accessible to DNase !

Question 5

Euchromatin

Answer 5

Transcriptionally active and accessible to DNase I

Question 6

Hypersensitive sites

Answer 6

Sections of chromatin (Usually in control regions) that are very sensitive to DNase I

Question 7

Stages of gene activition

Answer 7

Stage I makes the DNA available in the form of euchromatin and Stage II turns on the gene

Question 8

Locus Control regions

Answer 8

Regulate chromatin organization over chromosomal domains (Long periods of DNA)

Question 9

SWI-SNF

Answer 9

Alter chromatin structure using ATP, increases the mobility of nucleosomes throughout the genome

Question 10

Histone acetylation

Answer 10

Acetylates the lysine residues of the histone octomer, making it less basic and lowering association (increase acetylation= increase in expression)

Question 11

DNA methylation

Answer 11

Methyl groups added to CpG regions of DNA (esp promoters) to silence gene expression. Undergone by DNA methyltransferase

Question 12

Effects of DNA methylation on repair

Answer 12

Deamination of 5-methyl cytosine produces thymine instead of uracil, not recognized by repair machinery

Question 13

Enhancers

Answer 13

Regions of DNA anywhere in genome that can increase gene expression of a given gene

Question 14

Inducible gene expression

Answer 14

Gene can be turned on via signals and protein interaction

Question 15

Heat shock gene

Answer 15

Transcription factor that only activates when the cell is exposed to extreme heat

Question 16

DNA microarrays

Answer 16

Tells the difference in mRNA expression in two different cell lines. Colorful plates

Question 17

siRNA

Answer 17

Double stranded RNA with overhangs that bind to target RNA to “knock down” gene signaling

Question 18

RISC

Answer 18

RNA-induced silencing cimplex- allows aberrant RNA to be cleaved