Chapter 16

Question 1

promoter region

Answer 1

DNA sequence located upstream of the transcriptional start site

Question 2

TATA box

Answer 2

has the core DNA sequence 5’-TATAAA-3’ (usually located 25-35 bases pairs upstream of the transcription start site)

Question 3

transcription factors

Answer 3

proteins that bind to specific regions of DNA and regulate transcription

Question 4

negative regulation

Answer 4

a repressor protein prevents transcription (repressors)

Question 5

silencers

Answer 5

bind transcription factors that repress transcription

Question 6

positive regulation

Answer 6

an activator protein stimulates transcription (enhancers)

Question 7

enhancers can be ___ or ____ to the promoter region

Answer 7

proximal/distal

Question 8

epigenetics

Answer 8

study of heritable changes in gene expression that occur without changes in the DNA sequence

• CpG Islands
• -DNA methylation
• -Histone acetylation

Question 9

methyl group

Answer 9

covalently added to the 5’ carbon of cytosine

-methylation can “silence” some genes

Question 10

histone acetyltransferases

Answer 10

add acetyl groups to the tails which changes their charges and opens up the nucleosome to activate transcriptions

Question 11

histone deacetlases

Answer 11

removes the acetyl groups, which represses transcription

Question 12

euchromatin

Answer 12

diffuse, light-staining; contains DNA that is transcribed

Question 13

heterochromatin

Answer 13

condensed, dark-staining, contains genes not transcribed

Question 14

alternate splicing

Answer 14

different mRNAs can be made from the same gene

Question 15

small interfering RNA (siRNAs)

Answer 15

result in RNA silencing > translational inhibition