Chemical messengers

Question 1

receptor on cell is activated by a

Answer 1

ligand

Question 2

receptors have ____ ____ for ligands to attach to

Answer 2

binding sites

Question 3

binding of a ligand to a receptor causes a

Answer 3

response, signal transduction, change in the cell

Question 4

receptors are usually ___ proteins

Answer 4

transmembrane

Question 5

8 factors that determine the interaction between a ligand and receptor

Answer 5

specificity, affinity, saturation, competition, agonist, antagonist, downregulation, upregulation

Question 6

specificity

Answer 6

receptor’s ability to bind to a single or very limited type of ligand

Question 7

high specificity limits ____ with other ____

Answer 7

reactions, ligands

Question 8

a receptor is like a =

Answer 8

lock

Question 9

a ligand is like a =

Answer 9

key

Question 10

(lock and key analogy) : specificity

Answer 10

determines how close a key has to be in order to unlock the lock

Question 11

affinity

Answer 11

how strongly a receptor binds to a ligand

Question 12

if a ligand’s affinity to a receptor is strong then their connection will be ___ and can increase more ____ changes

Answer 12

longer, downstream

Question 13

if a ligand’s affinity to a receptor is weaker then their connection will be ___ and can last for a few ____

Answer 13

shorter, seconds

Question 14

competition

Answer 14

how effectively other similar compounds may be able to bind to the receptor

Question 15

example of competition

Answer 15

carbon monoxide competes with O2

Question 16

agonist

Answer 16

competes with normal chemical messenger, but triggers the same receptor response

Question 17

an agonist ___ natural ____

Answer 17

enhances, activity

Question 18

antagonist

Answer 18

competes with ligand, but doesn’t trigger same receptor response

Question 19

an antagonist blocks

Answer 19

signal transduction

Question 20

downregulation

Answer 20

decrease in the number of reven

Question 21

downregulation is usually in response to

Answer 21

an increased concentration of ligands

Question 22

upregulation

Answer 22

increase in receptors

Question 23

medications are all about ____

Answer 23

receptors

Question 24

the binding of a ligand to a receptor causes a ____ change that then leads to ____ activation

Answer 24

conformational, receptor

Question 25

when the signal transduction pathway is activated, it leads to a

Answer 25

response in the cell

Question 26

allosteric modulation

Answer 26

affinity of ligand to functional site on a receptor (protein) is dependent on the conformational change of a functional site due to the binding of a modulator protein to a regulator site

Question 27

functional site

Answer 27

where ligand binds to receptor in order to lead to physiologic processes

Question 28

the binding of a ligand to a functional site can alter other _____ sites on a multimeric protein

Answer 28

functional

Question 29

multimeric protein

Answer 29

protein made of multiple subunits with multiple binding/functional sites

Question 30

example of a receptor being influenced by the bonding of a ligand on a functional site of a multimeric protein

Answer 30

4 sites for O2 to bind to HGB and the first O2 to attach is the hardest, but once it binds the other 3 functional sites for O2 to bind become more cooperative (steeper positive curve)

Question 31

covalent modulation

Answer 31

the conformational change of a functional site in order to allow a ligand to bond is caused by a chemical reaction, most often phosphorylation

Question 32

in covalent modulation, there's a ___ change and changes in _____ distribution

Answer 32

conformational, electrical

Question 32

most common process used in covalent modulation

Answer 32

phosphorylation

Question 32

enzyme needed to add a negatively charged phosphate group

Answer 32

protein kinase

Question 32

phosphorylation

Answer 32

adds a negatively charged phosphate group

Question 33

what compound is required for phosphorylation, aka what does the protein kinase take a phosphate group from to add it to the charged groups of a receptor protein

Answer 33

ATP

Question 33

enzyme needed to remove a negatively charged phosphate group

Answer 33

protein phosphatase

Question 34

properties of lipid soluble messengers

Answer 34

can penetrate phospholipid membranes, receptors usually in nucleus, binding can lead to gene transcription/ protein synthesis or inhibit it

Question 35

properties of water soluble messengers

Answer 35

cannot penetrate membranes, bind to receptors at cell membrane

Question 36

examples of water soluble messengers

Answer 36

neurotransmitters, hormones, paracrine agents, autocrine agents

Question 37

receptor activation done by first messengers (water soluble messengers) can cause

Answer 37

activation of a second messenger in the cell and a cellular response

Question 38

a receptor acting as an ion channel is activated by a ____ which causes a ____ change that opens an ____

Answer 38

ligand, conformational, ion channel

Question 39

ions move through an ion channel in the membrane through ____ and an _____ ____

Answer 39

diffusion, electrochemical gradient

Question 40

the diffusion of ions through an ion channel ___ and ___ of the membrane can trigger some sort of

Answer 40

in, out, a cellular response or interaction

Question 41

2 examples of what a receptor can act as

Answer 41

ion channel, enzyme

Question 42

when a receptor acts as an enzyme, the receptor has direct __ activity

Answer 42

protein kinase

Question 43

if receptors act like an enzyme, they usually have a ___ group

Answer 43

tyrosine

Question 44

ligand binding to a receptor protein that acts as an enzyme activates its ___ portion

Answer 44

enzymatic

Question 45

when a receptor tyrosine kinase is activated by a ligand then it ____ itself

Answer 45

autophosphorylates

Question 46

after auto phosphorylating, the receptor binds to other ___

Answer 46

cytoplasmic proteins

Question 47

Arachadonic acid is a ___

Answer 47

polyunsaturated fatty acid

Question 48

arachadonic acid leads to the formation of

Answer 48

eicosanoids

Question 49

eicosanoids are usually released and act locally, so they act as either ___ or ___ agents

Answer 49

paracrine, autocrine

Question 50

arachadonic acid is formed by a ___ ____ activating ____ which splits arachadonic acid off of a ____

Answer 50

first messenger, phospholipase A2, phospholipid

Question 51

what activates the split between arachadonic acid and a phospholipid

Answer 51

phospholipase A2

Question 52

arachadonic acid can travel down ___ different pathways

Answer 52

2

Question 53

2 pathways that arachadonic acid can take

Answer 53

cycloogygenase pathway and lipoxygenase pathway