Gene Regulation

Question 1

Operon

Answer 1

Specific to prokaryotes. It is the promoter, the operator and the genes to be transcribed.

Question 2

Promoter Sequence

Answer 2

Region/site of DNA where RNA Polymerase attaches/binds to DNA and initiates transcription. Both prokaryotes and eukaryotes have them.

Question 3

Operater Sequence

Answer 3

DNA sequence that acts as an on/off switch, it controls access of RNA Polymerase to genes.

Question 4

Repressible Operon

Answer 4

Usually on, can be turned off

Question 5

Inducible Operon

Answer 5

Usually Off but can be turned on

Question 6

Euchromatin

Answer 6

Histones that are in a loose configuration, which allows RNA Polymerase to access them easily to carry out transcription

Question 7

Heterochromatin

Answer 7

Densely and compactly arranged chromatin, not accessible to the proteins that carry out transcription (RNA Polymerase)

Question 8

Chromatin

Answer 8

A complex of DNA and proteins known as histones, DNA wraps around histones and helps to organize packaging.

Question 9

Methods of changing chromatin structure

Answer 9

Chemical reactions and enzymes, chiefly acetylation and methylation

Question 10

Histone Acetylation

Answer 10

forms euchromatin through the addition of an acetyl group (-C0CH3) by an enzyme (acetyltransferase) to a histone tail promotes transcription by opening up chromatin structure,

Question 11

Histone/DNA Methylation

Answer 11

Forms heterochromatin through the addition of a methyl group (-CH3) to a histone or DNA, which decreases transcription by condensing chromatin

Question 12

Deacetylation

Answer 12

Reverses the acetylation process, condesning or closing the structure, making it heterochromatin

Question 13

Epigenetics Overview

Answer 13

Your DNA sequence is not the end all be all, genes can be methylated or deactivated through lifestyle choices and decreases stress. These epigenetic alterations can be passed to offspring.