Chapter 14

Question 1

Ligand

Answer 1

Small messenger molecules

Question 2

Second Messengers

Answer 2

Molecules produced in the target cell that relay the message from one part of the cell to another

Question 3

Receptor Affinity

Answer 3

How easy it is for a ligand to bind to its receptor

Question 4

Kd

Answer 4

Dissociation constant- how much ligand is needed to trigger a response (low Kd = high affinity)

Question 5

What is the relationship between Kd and receptor affinity

Answer 5

Inverse

Question 6

Receptor-Down Regulation

Answer 6

when receptors are bound to ligand for long periods the cell no longer responds to stimulus

Question 7

Receptor Mediated Endocytosis

Answer 7

receptors on cell surface are internalized

Question 8

Desensitization

Answer 8

receptor decreases its affinity for ligand

Question 9

Antagonist

Answer 9

inhibit the receptor by blocking the natural ligand from binding

Question 10

Agonist

Answer 10

drug that activate a receptor (morphine mimics endorphins)

Question 11

What are the pharmaceutical applications of cellular receptors?

Answer 11

synthesis of artificial ligands

Question 12

G-Protein Linked Receptors

Answer 12

family of receptors in which ligand bonding causes a change in conformation that activates a G-protein

Question 13

Protein Kinase-Associated Receptors

Answer 13

receptors are protein kinases, ligand binding activates the enzyme to add a phosphate group, causing phosphorylation events

Question 14

Protein Kinases

Answer 14

enzyme that adds a phosphate group

Question 15

What is the structure of G-protein linked receptors

Answer 15

7 transmembrane alpha helices

Question 16

Structure of Tyrosine Kinases

Answer 16

single polypeptide with 1 transmembrane domain

Question 17

Activation of Tyrosine Kinases

Answer 17

ligand binds and the receptors phosphorylate each other’s tyrosine residues

Question 18

What is Cyclic AMP?

Answer 18

ATP that has had the last two phosphates cut off and the remaining one is linked back to the sugar
caused by adenylylcyclase

Question 19

What is Cyclic AMP degraded by?

Answer 19

phosphodiesterase

Question 20

Growth Factors

Answer 20

ligands that can tell a cell to grow and divide

Question 21

What is epinephrine also known as?

Answer 21

Adrenaline

Question 22

What does insulin control?

Answer 22

blood glucose levels

Question 23

What do epinephrine and norepinephrine control?

Answer 23

Fight or flight

relaxes smooth muscle and diverts blood flow to the heart and lungs

Question 24

Apoptosis

Answer 24

programmed cell seppuku

Question 25

Caspases

Answer 25

enzymes responsible for protein cleavage

Question 26

Steps of apoptosis

Answer 26

1. volume of cell decreases
2. nucleus and organelles break apart
3. cell produces blebs
4. DNA degraded
5. dismantled into apoptic bodies
6. remnants engulfed by nearby cells

Question 27

What two things might degrade the DNA during apoptosis

Answer 27

endonuclease and DNAase

Question 28

What is something that might eat parts of a cell after it commits apoptosis?

Answer 28

macrophage

Question 29

Bcl2

Answer 29

anti-apoptic protein on mitochondria’s surface

Question 30

Cytochrome C

Answer 30

released from mitochondria to promote apoptosis

Question 31

P53

Answer 31

triggers apoptosis in response to cell damage

Question 32

Three ways to trigger apoptosis

Answer 32

binding of “death signals” to cellular receptors
withdrawal of survival factors from cellular receptors
DNA damage

Question 33

what degrades cyclic AMP

Answer 33

phosphodiesterase