Cell Receptors Week 2

Question 1

What is the function of Gated Ion Channels?

Answer 1

Open or close channels to allow certain ions to pass through the cell membrane

Question 2

What happens when a ligand binds to the receptor?

Answer 2

Produces a conformation change that widens or narrows the channel regulating access of soluble ions

Question 3

What is an example of a common gated ion channel receptor?

Answer 3

Nicotinic acetylcholine receptor — allows sodium and potassium to enter the cell causing cellular depolarization

Question 4

What is an example of a neurotransmitter that uses gated ion channels

Answer 4

Gamma - Aminobutyric Acid (GABA A) increases the opening of chloride channel

Question 5

Which cell receptor has its ligand-binding domain

Answer 5

Transmembranous Receptors

Question 6

Where is the enzymatic portion of the cell located?

Answer 6

In the cytoplasm

Question 7

Intracellular response is often a …..

Answer 7

change is enzymatic activity

Question 8

What happens during a transmembranous receptor?

Answer 8

receptor-ligand produces a conformation change in the receptor and triggers a response.
Or a ligand-receptor complex can pass through the cell
membrane and trigger an intracellular response.

Question 9

What is the key feature of transmembranous Receptors?

Answer 9

Downregulation and Upregulation

Question 10

What is Downregulation?

Answer 10

decrease in the number of receptors available

Question 11

What does a transmembranous receptor need in order to initiate a signal?

Answer 11

specific ligand - receptor interaction which commonly results in the generation of second messengers

Question 12

What type of receptor is Tyrosine Kinase?

Answer 12

Transmembranous Receptor

Question 13

What can Tyrosine Kinase bind to?

Answer 13

polypeptide hormone or growth factor at the receptors extracellular domain — activates tyrosine kinase that phosphorylate allowing a single receptor to activate multiple biochemical process

Question 14

What can occur if downregulation receptors are activated?

Answer 14

endocytosis of the receptor and subsequent receptor degradation — decrease in cell activity.

Question 15

Do G-Protein Coupled receptors initiate intra or extra cellular activity

Answer 15

Intracellular – another family of receptors that uses second messengers

Question 16

True or False: G-Protein coupled receptors are composed of an extracellular protein receptor and an intracellular type G protein

Answer 16

True

Question 17

What happens when a ligand and the receptor produces a conformational change and gets in contact with a G protein?

Answer 17

Activation of an enzyme or opening of an ion channel in the cell and causes increased levels of second messenger

Question 18

True or False: It is the second messenger that triggers a change in the function of a cell?

Answer 18

True

Question 19

Examples of G-protein receptors

Answer 19

Alpha and Beta adrenergic receptors along with several hormone receptors

Question 20

Out of all 4 receptors, which one can transverse the lipid bilayer and enter the cytoplasm of the cell?

Answer 20

Intracellular Receptors

Question 21

Out of all 4 receptors, which one affects the DNA transcription?

Answer 21

Intracellular Receptors

Question 22

True or False: Intracellular Receptors initiate direct changes to the cell

Answer 22

True

Question 23

Examples of Intracellular receptors

Answer 23

Glucocorticoids and sex hormones