Intracellular receptors

Question 1

Intracellular receptors are membrane bound, True or false?

Answer 1

False - not membrane bound

Question 2

Intracellular receptors are important in directly regulating ____ expression

Answer 2

gene

Question 3

Intracellular receptors are also known as __________ or __________

Answer 3

nuclear hormone receptors

nuclear transcription factors

Question 4

Sometimes the DNA binding region is called _______

Answer 4

zinc fingers

Question 5

The ligand binding site is at which terminal?

Answer 5

C-terminal

Question 6

The DNA binding region contains ____ cysteine residues

Answer 6

9

Question 7

How many of the cysteine residues can bind zinc ions?

Answer 7

8

Question 8

Zinc ions destabilise the DNA binding region. True or false?

Answer 8

False - they stabilise it

Question 9

How do intracellular receptors work?

Answer 9

ligand crosses the membrane, seeks a receptor and binds
Induced fit takes place and receptor changes shape - dimerisation
Dimer then binds a coactivator
Whole complex then binds to a specific region of the cell’s DNA

Question 10

What is oestrodiol?

Answer 10

A steroid hormone that affects the growth and development of tissues

Question 11

Oestrodiol uses its phenol and alcohol groups to form ______ bonds with three amino acids in the binding site

Answer 11

Hydrogen

Question 12

Breast cancer is _________ dependent

Answer 12

oestrogen

Question 13

What are the three ways in which oestrogen secretion can be reduced?

Answer 13

Oophorectomy
Hypophysectomy
Adrenalectomy

Question 14

Is taximofen a competitive or non-competitive inhibitor?

Answer 14

Competitive - it inhibits the binding of oestrogen to oestrogen receptors

Question 15

For oestrogen positive tumours, one year treatment with tamoxifen reduces recurrence and increases survival. True or false?

Answer 15

True