Hormone Signalling Pathway

Question 1

How much oestrogen is in the contraceptive pill?

Answer 1

35 micrograms

Question 2

What makes up 30% of cell membranes?

Answer 2

Lipids with an -OH group (alcohol)

Question 3

How much cell membrane is synthesised a day?

Answer 3

1g a day.

Question 4

Characteristics of steroid hormones:

Answer 4

Have both hydrophilic and hydrophobic properties.
Can penetrate through membranes

Question 5

What are the two types of steroid hormones?

Answer 5

Corticosteroids
Sex steroids

Question 6

Corticosteroids:

Answer 6

Mineralocorticoids
Glucocorticoids
(Made in adrenal cortex)

Question 7

Sex steroids:

Answer 7

Androgens
Progesterone
Oestrogen
(Made in gonads / placenta)

Question 8

What is a DNA binding domain made of?

Answer 8

4 cystine residues and a zinc atom.
Forms a loop which can access the major groove of DNA.

Question 9

What phases make up the transcriptional response to nuclear receptor stimulation?

Answer 9

Primary response phase
Secondary response phase

Question 10

What happens in the primary response phase of transcriptional response?

Answer 10

Receptor-hormone complex switches on primary response genes.
Primary response proteins are synthesised.

Question 11

What happens in the secondary response phase of transcriptional response?

Answer 11

The primary response proteins switch OFF primary response gene expression.
Primary response proteins switch ON secondary response gene expression.
Secondary response proteins are synthesised.

Question 12

What is a glucocorticoid receptor?

Answer 12

Mediates actions of glucocorticoids.

Question 13

What is a glucocorticoid?

Answer 13

Immunosuppressant and anti-inflammatory agent.

Question 14

What are the side effects of glucocorticoids?

Answer 14

Bone loss, glucose dysregulation.

Question 15

What is the hypothalamic pituitary axis?

Answer 15

Releases ACTH and CRH
Stress response and regulates sugar levels

Question 16

What is Addison’s disease?

Answer 16

TOO LITTLE CORTISOL
Causes damage to adrenal glands
Lack of ACTH.
Depression, flu like symptoms, weight loss.

Question 17

What is an Adison’s crisis?

Answer 17

Caused by sudden stress, E.g. an operation, accident, infection.

Question 18

What is Cushings syndrome?

Answer 18

TOO MUCH CORITSOL
Can be caused by an adenoma growing on adrenal glands, causing increased ACTH production.
Weight gain, high blood pressure, puffy face.
Caused by steroid use / abuse.

Question 19

What are the 3 steps of insulin signalling?

Answer 19

1. Tyrosine kinase phosphorylates receptor and its substrates
2. Activation of lipid kinase (P13K)
3. Activation of AKT

Question 20

What does AKT phosphorylate?

Answer 20

Tyrosine / Serine residues
(FOXO transcription factors, TSC2, MTORC1, S6K, SREBP1c, GSK3, TBC1D4)

Question 21

What is type I diabetes?

Answer 21

Destruction of beta cells, often caused by an auto-immune attack.

Question 22

What is type II diabetes mellitus?

Answer 22

Dysregulation of metabolism, impaired insulin direction / insulin resistance.

Question 23

What is the treatment for type II diabetes?

Answer 23

Metformin. It decreases insulin resistance and promotes weight loss. It activates AMPK which regulates glucose metabolism.
It is positively charged so it accumulates in cell and mitochondria membranes.