Cellular control

Question 1

What are the three ways to control gene expression?

Answer 1

Transcriptional
Post-transcriptional
Post-translational

Question 2

What is transcriptional factors?

Answer 2

Proteins that bind to DNA and switch genes on or off by increasing or decreasing the rate of transcription

Question 3

What is activatiors and repressors?

Answer 3

• Activators - Factors that start transcription
• Repressors - Factors that stop transcription

Question 4

How does molecules in the environment control gene expression?

Answer 4

• The shape of a transcriptional factor can be altered by the binding of some molecules
• This determines whether it can bind to DNA or not

Question 5

What is an operon?

Answer 5

a section of DNA that contains a cluster of structural genes that are all transcribed together, as well as control elements and sometimes a regulatory gene

Question 6

What is the structural genes?

Answer 6

code for useful proteins, such as enzymes

Question 7

What is a promotor?

Answer 7

a DNA sequence located before the structural genes that RNA polymerase binds to

Question 8

What is an operator?

Answer 8

A DNA sequence that transcription factors bind to

Question 9

What is the regulatory gene codes for?

Answer 9

activator or repressor

Question 10

How does gene expression control by post-transcriptional level control?

Answer 10

After tanscriptional, mRNA in eukaryotic cells is edited because genes in eukaryotic DNA contain sections that don’t code for amino acids

Question 11

What is introns?

Answer 11

DNA sections that don’t code for amino acids

Question 12

What is exons?

Answer 12

All the bits that do code for amino acids are called exons

Question 13

Describe how gene expression is controlled during post-transcriptional level

Answer 13

1. mRNA strand containing introns and exons are called primary mRNA transcripts
2. Introns are removed from primary mRNA strands by a process called splicing
3. Exons are joined together to form mature mRNA strands.
4. This takes place in the nucleus.
5. The mature mRNA then leaves the nucleus for the next stage of protein synthesis

Question 14

Describe how post transcriptional level control gene expression?

Answer 14

Some proteins need to be activated to work
cAMP activates proteins inside the cell by altering their 3D structure