Hormone Synthesis And Action

Question 1

What are the two types of hormones (in terms of synthesis and action) ?

Answer 1

Peptides and proteins

steroids and iodinated tyrosines

Question 2

How are proteins/ peptide hormones synthesised?

Answer 2

Transcription

Question 3

What are the parts of pre-prohormones?

Answer 3

Signal + hormone + peptide sequences

Question 4

What are the parts of the prohormone?

Answer 4

Hormone + peptide sequences

Question 5

What parts of the endocrine system are controlled by the hypothalmic- pituitary axis?

Answer 5

Thyroid, adrenal cortex and gonads

Question 6

What does stAR stand for?

Answer 6

Steroidogenic acute regulatory protein

Question 7

What is scc?

Answer 7

Cytochrome C

Question 8

What is T3 made up of?

Answer 8

One monoiodinated tyrosine and one diiodinated tyrosine

Question 9

What is T4 made up of?

Answer 9

Two diiodinated tyrosines

Question 10

What is the general action of peptide and protein hormones?

Answer 10

Activate second messengers and/ or enzymes

Question 11

What is a G protein coupled receptor made up of?

Answer 11

7 transmembrane binding domains, one extracellular binding domain (N terminus)
One intracellular domain (C terminus)

Question 12

What are receptor tyrosine kinases made up of?

Answer 12

One transmembrane domain
one extracellular binding domain (N terminus)
One intracellular binding domain bound to a tyrosine kinase domain

Question 13

What are the names of the two types of signalling pathway related to GPCRs?

Answer 13

Adenyl cyclase and cAMP signalling pathway

Phosphoinositide signalling pathway

Question 14

What are the names of the two types of signalling pathway related to tyrosine kinase receptors?

Answer 14

Raf/MEK/ERK1/2 pathway

PI3 kinase/AKT signalling pathway

Question 15

What are steroid hormone receptors?

Answer 15

A family of transcription factors

Question 16

What are the different functional regions of the receptor called?

Answer 16

Domains A-F

Question 17

What is the function of the c domain?

Answer 17

DNA binding region

Question 18

What do both the A/B and E/F domains do?

Answer 18

Transcriptional activity

Question 19

What does the E domain do?

Answer 19

Ligand binding domain

Question 20

What does C domain contain and how does it help its function?

Answer 20

Zinc fingers that allow part of the transcription factor to bind to DNA

Question 21

What are the two possible causes of insufficient insulin?

Answer 21

Type 1 and type 2 diabetes

Question 22

What happens in type 1 diabetes?

Answer 22

Autoimmune destruction of pancreatic islets -> absolute insulin deficiency

Question 23

What happens in type 2 diabetes?

Answer 23

Insulin resistance, partial loss of insulin production (insulinopaenia)

Question 24

What does insulin resistance lead to?

Answer 24

Hyperglycaemia, dyslipadaemia, hypertension, endothelial dysfunction, inflammation and impaired thrombolysis

Question 25

What happens if there’s an aromatase deficiency in men?

Answer 25

Can’t synthesise oestrogens from androgens -> no epiphyseal closure -> long stature and elongated bones

Question 26

What happens if there’s an aromatase deficiency in women?

Answer 26

Virilisation of XX foetuses Cliteromegaly Ambiguous genetalia

Question 27

What does an enlargement of the thyroid gland cause?

Answer 27

Lack of iodine in the diet -> T3/4 deficiency Graves’ disease Thyroid adenoma

Question 28

What is Graves’ disease?

Answer 28

Hyperthyroidism

Question 29

What happens in Graves’ disease?

Answer 29

Autoantibodies in the TSH receptor act on the thyroid gland to stimulate excess thyroid hormone