Assessment 3, Part 2

Question 1

what are the 3 different types of receptors?

Answer 1

1. membrane bound
2. nuclear
3. cytoplasmic receptors

Question 2

what are the 2 main types of membrane bound receptors?

Answer 2

1. GPCRs

2. Thyrosine Kinase Receptors

Question 3

What are 3 examples of Gs receptors? where are they found?

Answer 3

1. Beta Adrenergic Receptor; found on smooth muscle cells of the coronary arteries
2. Vasopressin Type 2 Receptor;
3. Thyroid Stimulating Hormone; plasma membrane of the thyroid follicles

Question 4

What are 3 Examples of Gq receptors?

Answer 4

1. Thyroid Releasing Hormone; plasma membrane of thyrotropes
2. Alpha Adrenergic Receptor;smooth muscle cells of peripheral blood vessels (skin, etc.)
3. Vasopressin Type 2 Receptor; smooth muscle cells in the arterioles of the kidneys

Question 5

What is an example of a cytoplasmic receptor?

Answer 5

ANY steroid hormone

Question 6

What is an example of a nuclear receptor?

Answer 6

T3/T4

Question 7

what do alpha adrenergic receptors do?

Answer 7

bind to epinephrine and cause the smooth muscle cells of the peripheral blood vessels to vasoconstrict (blocking off vessels to the skin, etc. and sending more blood to the heart and skeletal muscles)

Question 8

what do vasopressin type 1 receptors do?

Answer 8

bind to AVP and causes arterioles of the kidney to contract. this cause the filtrate/blood to slow down and the filtration rate to decrease. this leads to water retention

Question 9

what do beta adrenergic receptors do?

Answer 9

bind to epinephrine causing the smooth muscle cells of the coronary artery to RELAX. this makes the coronary artery vasodialate which leads to increased heart rate and therefore increases the blood pressure

Question 10

what do vasopressin type 2 receptors do?

Answer 10

bind to AVP and cause the cells of the collecting duct to open aquaporin channels which return water back to the circulation. this leads to water retention

Question 11

what is a tyrosine kinase receptor?

Answer 11

a receptor that binds with a ligand to activate the autophosphorylation of tyrosine units, leading to activation of many enzymatic reactions

Question 12

what happens when insulin binds to hepatocytes?

Answer 12

glucose is used to make glycogen which decreases the glucose level in the blood

Question 13

what happens when insulin binds to skeletal muscle cells?

Answer 13

glucose is used for energy production during aerobic cellular respiration

Question 14

what is the term for a hormone that penetrates phospholipid membranes and binds to a cytoplasmic receptor?

Answer 14

lipophylic/hydrophobic

Question 15

why do steroids add proteins to muscles?

Answer 15

the translocation of cytoplasmic receptors from the cytoplasm to its binding site on DNA initiates gene transcription and translation for gene expression

Question 16

What is TPO? what are its 3 main functions?

Answer 16

thyroid peroxidase:

1. oxidation: iodide into iodine
2. organification: incorporation of iodine into the tyrosine units of Tg to synthesize MIT and DIT
3. coupling of MIT and DIT to make T3 and T4

Question 17

what is Tg?

Answer 17

a large protein carrying MIT and DIT

Question 18

what is deiodinase?

Answer 18

an enzyme that converts T4 into T3, because only T3 can penetrate the nuclear envelope/membrane to bind to DNA and cause gene expression for TSH