Lecture 15

Question 1

What is the central dogma of molecular biology?

Answer 1

The flow of information from DNA to mRNA in make a peptide chain which can undergo post-translational modification to fold into a protein

Question 2

What is transcription?

Answer 2

DNA -> mRNA

Question 3

What is transaltion?

Answer 3

mRNA -> peptide chain

Question 4

What is mRNA?

Answer 4

Messenger RNA

Question 5

What is a gene?

Answer 5

A region of DNA that provides instructions to make an RNA molecule

Question 6

What is the promoter region of a gene?

Answer 6

The region that controls gene expression

Question 7

What is the transcribed region of a gene?

Answer 7

The region of the gene that is copied into mRNA

Question 8

In eukaryotic genes, what does the transcribed region contain?

Answer 8

Exons and introns

Question 9

What are the exons?

Answer 9

The translated regions of the gene

Question 10

What are the introns?

Answer 10

The untranslated regions of the gene

Question 11

How are introns removed before translation?

Answer 11

Through splicing

Question 12

Do prokaryote cells have have introns?

Answer 12

No

Question 13

What is RNA polymerase?

Answer 13

The enzyme that makes the mRNA

Question 14

How does RNA polymerase work?

Answer 14

Uses the DNA as a template to make the mRNA which will have the exact same sequence as one of the two DNA stands

Question 15

What is the difference between bases in DNA and RNA?

Answer 15

DNA = T (thymine)
RNA = U (uracil)

Question 16

In eukaryotes, where is the mRNA transcribed?

Answer 16

In the nucleus of the cell

Question 17

In eukaryotes what must happen to the mRNA before translation?

Answer 17

Must be processed and undergo splicing to remove the introns. Protective elements added to prevent degradation

Question 18

In eukaryotes, where does translation occur?

Answer 18

On the free ribosomes in the cytosol

Question 19

What part of a gene controls transcription?

Answer 19

The promoter region

Question 20

What does the promoter region contain?

Answer 20

The transcription factor binding sites and RNA polymerase binding site

Question 21

When is gene expression turned on?

Answer 21

When it is transcribed

Question 22

What is RNA polymerase?

Answer 22

The enzyme that makes mRNA. It must be told to bind to a promotor before any mRNA can be made

Question 23

What are transcription factors?

Answer 23

Proteins that bind DNA and control promotor binding of RNA polymerase

Question 24

What are the two kinds of transcription factors?

Answer 24

Activators which turn on gene expression and repressors which turn off gene expression

Question 25

What do transcription factor activators do?

Answer 25

Encourage RNA polymerase binding and the creation of mRNA (transcription)

Question 26

What do transcription factor repressors do?

Answer 26

Prevent RNA polymerase from binding and prevent mRNA from being made

Question 27

What sort of contact do transcription factors use to control expression?

Answer 27

Physical connections

Question 28

Why is transcriptional control important?

Answer 28

To determine when, and how much of something needs to be made. It is essential for making cells different to eachother

Question 29

Are the type of transcription factors present in a cell fixed or dynamic?

Answer 29

Dynamic, can change over time from the receptor proteins and their signalling cascades based on the cells environment