Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Biochemistry, genetics, and metabolism > cell signaling > Flashcards

cell signaling Flashcards

You may prefer our related Brainscape-certified flashcards:
Biology 101 flashcards
1
Q

Type of signaling

A

regulatory signals that originate from conditions within the cell.
communication signals that occur between two neighboring cells.
Response to extracellular regulatory signals that are generated to coordinate metabolic activities and other activities essential for the development and survival of organisms.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

model for initiating a cellular response to an extracellular signal

A
  1. Unoccupied receptor does not interact with G(s) protein.
  2. Occupied receptor changes shape and interacts with G(s) protein. G(s) protein releases GDP and binds GTP.
  3. Alpha subunit of G(s) protein dissociates and activates adenylyl cyclase
  4. When hormone is no longer present, the receptor reverts to resting state. GTP on the alpha subunit is hydrolyzed to GDP, and adenylyl cyclase is deactivated
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is an important receptor in pharmacology?

A

G-protein coupled receptors

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

G-protein coupled receptors

A

a family of integral membrane cell surface receptors

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What are G-proteins characterized by?

A
  1. an extracellular ligand-binding domain
  2. seven transmembrane spanning domains
  3. a cytosolic G-protein activation domain
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

G-protein coupled receptors and ligands

A

bind to specific ligand. conformational changes due to ligand binding are transmitted to the interior of the cell.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Beta and Gamma subunits of the G-protein

A

act as membrane localizes docking site for the inactive alpha subunit. anchor for alpha

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

alpha subunit

A
  1. binds guanosine nucleotides (GTP/GDP)

1. the inherent ability to hydrolyze GTP to GDP, this is what turns it off.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

depending on its activation state, the alpha subunit can interact with..

A

a specific activated GPCR or adenylyl cyclase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What determines if a g-protein functions to stimulate (Gs) or inhibit (Gi) adenylyl cyclase?

A

which family of G protein is linked to a GPCR in a cell type

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Adenylyl Cyclase

A

integral membrane enzyme. Enzymatic activity can be stimulated or inhibited by several different proteins, enzymatically utilizes energy from hydrolysis of ATP->AMP + PPi to form cAMP. Generated cAMP quickly

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

cAMP

A

second messenger produced by adenylyl cyclase.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is the target of cAMP

A

family of enzymes called protein kinases

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Protein Kinase A

A

2 regulatory subunits, 2 catalytic subunits

Catalytic subunits can phosphorylate intracellular effectors.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

How does cAMP and protein kinase A work together?

A

cAMP docks with the protein kinase A regulatory cAMP binding sites, and the protein kinase A catalytic subunits are released.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What do active protein kinase A catalytic subunits do?

A

phosphorylate target proteins and enzymes to elicit the function of intracellular effectors driven by extracellular signals

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

intracellular effectors

A

ion channels, enzymes, DNA binding proteins.

18
Q

Phosphorylation

A

can positively or negatively affect the activity of an intracellular effector. It does NOT always turn something on.

19
Q

protein phosphatases

A

enzymes that hydrolytically cleave phosphate esters and thus remove/dephosphorylate effector proteins that are phosphorylated by protein kinases

20
Q

Which amino acids can be phosphorylated

A

Serine, threonine, tyrosine. they contain an -OH functional group

21
Q

cAMP phosphodiesterase

A

is an enzyme that rapidly converts cAMP to 5’-AMP (NOT a signaling molecule)

22
Q

Disruption of normal adenylyl cyclase activity

A

A1 interacts with ADP-ribosylation factors, which catalyzes ADP-ribosylation of G alpha so it can never turn off

23
Q

What is the regulation pathway for intermediary metabolism?

A

inositol triphosphate and Diacylglycerol signaling

24
Q

phospholipase C

A

membrane localized, cleaves lipid bilayer PIP2-IP3 and DAG

25
Q

IP3

A

inositol 1,4,5-triphosphate binds ER receptor, releasing Ca2+ from ER to cytosol

26
Q

PIP2

A

Phosphatidylinositol 4,5-biphosphate is a membrane phospholipid

27
Q

Protein Kinase C

A

major target activated by DAG and Ca2+, functions with Ca2+ to synergystically promote (metabolic) responses by phosphorylating proteins, it is cAMP dependent. What promotes change in cellular program

28
Q

What ligand stimulate IP3 and DAG signaling

A

nurotransmitters, hormones, and growth factors

29
Q

Ca2+ as a signaling molecule in the liver

A

calcium released from ER, 4 calcium bind to calmodulin, calmodulin-Ca complex results in a conformational change that permits interactions with and activation of enzymes involved in metabolism

30
Q

coordination of energy metabolism is controlled by

A

Primary-two peptide hormones-insulin and glucagon

Supporting-two catecholamines-epinephrine and norepinephrine

31
Q

insulin

A

a protein hormone that is water soluble
produced in beta cells in the islets of Langerhans in the pancreas
stored in secretory granules
anabolic effector

32
Q

what does insulin promote

A

production of glycogen, triacylglycerides, protein

33
Q

regulation of insulin secretion

A

beta cell secretion of insulin is coordinated with alpha cell secretion of glucagon

34
Q

the rate of glucose use by peripheral tissues as a result of insulin secretion is counter balanced by

A

glucagon release, hepatic glucose production rates

35
Q

increased insulin secretion from glucose

A

results in coordinated increase in insulin rate, beta cells produce more insulin, glucagon levels decrease

36
Q

increased insulin secretion from amino acids

A

increased amino acid concentration and insulin secretion stimulated, glucagon release is unregulated to compensate for the increased insulin and thus glucose uptake

37
Q

increased insulin secretion from GI hormones

A

peptide hormones are released from the small intestine as anticipatory insulin release stimulators in response to food ingestion, insulin secretion is greater when glucose is ingested in contrast to given IV

38
Q

factors that negatively affect insulin secretion

A

scarcity of dietary fuels such as glucose and amino acids

Increase in blood levels of epinephrine

39
Q

Epinephrine release is regulated by the nervous system and is secreted by the adrenal medulla in response to

A

stress, trauma, extreme exercise

40
Q

epinephrine directly affects mobilization of

A

glucose from the liver

fatty acids from adipose tissue

41
Q

what can override the normal glucose-stimulated release of insulin?

A

epinephrine

Biochemistry, genetics, and metabolism (11 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions