lecture 15 - how genes make cells

Question 1

What is transcriptional control?

Answer 1

A process that determine when and in what cells a gene is transcribed to produced mRNA and eventually proteins

Question 2

What is transcription?

Answer 2

The process in which a DNA sequence is copied into an mRNA molecule to express specific genes

Question 3

What is the key component of the regulatory region of a gene?

Answer 3

The promoter

Question 4

What is the promoter region of a gene?

Answer 4

A regulatory region - the DNA sequence at which transcription factors bind to short sequences and recruit RNA polymerase

Question 5

What is the transcribed region of DNA in transcription?

Answer 5

Sequences of DNA that are copied into RNA to form pre-mRNA, before they are spliced for intron removal and further processes to form a final mRNA transcript that can be translated.

Question 6

What are the 2 types of transcription factor?

Answer 6

Activators and repressor

Question 7

What is the transcription factor requirement for transcription?

Answer 7

Genes are only expressed when all the necessary activator transcription factors are present AND the repressor is absent

Question 8

Why is the insulin protein only translated in Pancreatic B cells?

Answer 8

Because the gene can only be expressed when a transcription factor, made only only in Pancreatic B cells, is present

Question 9

How is insulin gene expression in pancreatic B cells ‘turned off’?

Answer 9

Leptin, a hormone made in fat and gut cells, signals to the B cells via a receptor, leading to signal transduction and the production of an active repressor that stops genes expression