Gene Expression

Question 1

What is ‘Gene Expression’?

Answer 1

This is the range of mechanisms used by the cells in order to INCREASE / DECREASE production of specific gene products.

Question 2

What are the 4 types of cell types?

Answer 2

• Epithelial
• Connective
• Muscle
• Nervous

Question 3

What is the purpose of epithelial cells?

Answer 3

Cells are attached to one another = covers the interior of hollow organs.

Question 4

What is the purpose of connective cells?

Answer 4

Provided structural strength to the body

Defends AGAINST foreign invaders like bacteria.

Question 5

What is the purpose of muscle cells?

Answer 5

Specialised for contraction.

Question 6

What are the 3 types of muscle cells?

Answer 6

Skeletal
Cardiac
Smooth

Question 7

What is the purpose of nerve cells?

Answer 7

Specialised for communication.

These send signals from the brain to the muscles.

Question 8

How many different types of cells are there in humans?

Answer 8

200 different cell types.

Question 9

Why is variation essential in gene expression?

Answer 9

Helps to identify cellular mechanisms.

Question 10

What is a loci?

Answer 10

A specific fixed position on a chromosome where a particular gene is located.

Question 11

What is the human tissue proteome?

Answer 11

This is an ENTIRE set of proteins which is expressed by a genome.
There are over 20,000 proteins in the human proteome.

Question 12

What are housekeeping genes?

Answer 12

These are crucial for the maintenance of BASIC cellular function.

Question 13

What are some examples of housekeeping genes?

Answer 13

Actin
Ubiquitin
GAPDH
These are used for the maintenance and sustenance of a cell.

Question 14

How many housekeeping genes are there?

Answer 14

7319

Question 15

What are tissue elevated genes?

Answer 15

These genes are distinguished by gene expression = they are SPECIFIC in more than one tissue.

Question 16

Where are tissue elevated genes mainly found?

Answer 16

69% is found in the duodenum = which is in the small intestine.

Question 17

What is gene expression regulation?

Answer 17

This is the process by which the GENETC CODE of a gene is used to direct protein synthesis and produce structures of the cell.

Question 18

What is the genetic code?

Answer 18

Nucleotide sequence.

Question 19

What is the purpose of gene expression regulation?

Answer 19

This is a wide range of mechanisms which are used in order to INCREASE // DECREASE production of specific gene products.

Question 20

What are structural genes?

Answer 20

These genes code for amino acid sequences.

Question 21

What are transcription factors?

Answer 21

These regulate the transcription of genes and bind to specific DNA sequences in order to regulate the expression of a given gene.

Question 22

What are the 2 types of transcription factors?

Answer 22

Activators

Repressors

Question 23

What is the purpose of activators as transcription factors?

Answer 23

These boost transcription

Question 24

What is the purpose of repressors as transcription factors?

Answer 24

These decrease transcription

Question 25

What is the promoter?

Answer 25

This is where the RNA molecules attaches to the DNA of the gene.

Question 26

What is the purpose of the promoter?

Answer 26

This allows the initiation of transcription of a particular gene.

Question 27

Where is the promoter region located?

Answer 27

Located at the 5’ end of the transcription site.

Question 28

What is the sense strand?

Answer 28

Where DNA will be transcribed.

Question 29

What is a TATA box?

Answer 29

This is a conserved promoter sequence.

Question 30

Where is the TATA box found?

Answer 30

It is found on the 5’ strand.

Question 31

What is the purpose of the TATA box?

Answer 31

Transcription factors bind to the TATA box and thus initiates the formation of the RNA polymerase which in turn PROMOTES TRANSCRIPTION.

Question 32

What is transcriptional regulation?

Answer 32

This is where the cell regulates conversion from DNA to RNA = known as GENE ACTIVITY.

Question 33

What happens during transcriptional regulation?

Answer 33

Produces shortening of the DNA molecule and activation alongside repression.

Question 34

During what process does transcriptional regulation occur?

Answer 34

Occurs in DNA looping.

Question 35

What is an inducible gene?

Answer 35

This a gene whose expression is responsible to environment change and is dependent on the position in the cell cycle.

Question 36

Why are oestrogen receptors important for inducible gene transcription?

Answer 36

It is important as it CONTROLS physiological functions ini reproductive organs = Plays a PIVOTAL role.

Question 37

What category does oestrogen receptors fall into?

Answer 37

Ligand inducible transcription factor.

Question 38

What is the COMMON form of gene control?

Answer 38

Regulatory Transcription Factors.

Question 39

What happens with general transcription factors ?

Answer 39

Binds directly to special promoter region.

Question 40

What do transcription factors normally do?

Answer 40

They interact with the CORE promoter region.

Question 41

What is tamoxifen?

Answer 41

An antagonist.

This is an oestrogen blocker which is found in the opening of the cells = PREVENTS OESTROGEN CANCERS.

Question 42

What is the purpose of tamoxifen?

Answer 42

They bind to the oestrogen receptor and can INCREASE oestrogen levels in women.

Question 43

What is the purpose of early embryogenesis?

Answer 43

This is a cell cycle control and is what occurs in the (1st) 8 weeks of development after fertilisation.

Question 44

Why is translational control important?

Answer 44

It is essential as it initiates functions.