Gene regulation (Part 1) Flashcards Preview

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Flashcards in Gene regulation (Part 1) Deck (14):
1

Prokaryotes differ from Eukaryotes in that they lack...

A cell nucleus and specialized membrane-bound organelles.

2

What is the difference between constitutive and regulate genes?

Constitutive genes: Always on

Regulated genes: Only required under certain conditions

3

In bacteria, the amount of mRNA dictates protein synthesis and thus amount of protein, controlling its activity. (T/F)

TRUE

4

Bacterial operons are ____.

Polycistronic

(Meaning: single mRNA encodes for several polypeptide chains

5

What are the two main types of regulatory proteins in bacteria?

- Negative regulation
- Positive regulation

6

How does negative regulation regulate transcription in bacteria?

Through repressors which bind to an operator and prevent RNA polymerase initiating transcription

7

How does positive regulation regulate transcription in bacteria?

Through activators which bind to an operator and allow RNA polymerase to initiate transcription.

8

In bacteria, a gene cannot use both types of regulation (T/F)

FALSE!!

A gene CAN use both Negative and Positive regulation.

9

What is the lac operon and what is its role?

Lac Operon: 6000 bp long collection of genes involved in sugar metabolism (Lactose)

- Metabolize the sugar "lactose" if there are no other energy source

10

How many proteins are coded in the lac operon?

3

11

What are the proteins coded by the Lac Operon?

Lac Z - Beta-galactosidase
Lac Y - lactose permease
Lac A - Transacetylase

12

What occurs at the Lac O region of the Lac Operon?

O= Operator; main 'switch' - binds repressor protein

13

What occurs at the Lac P region of the Lac Operon?

P= Promoter; binds to RNA polymerase

14

What occurs at the Lac I region of the Lac Operon?

Lac Repressor - turns gene off


(Regulatory protein)