Brainscape's Knowledge GenomeTM

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


See full index

Molecular Test III > Lecture 18 Cell Communication > Flashcards

Lecture 18 Cell Communication Flashcards

1
Q

Where does signal transduction occur?

A

inside the cell

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

What is signal tranduction?

A

Process in which Extracellular signaling molecules bind to specific receptors in target cells to initiate a chain of events

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

External signals induce what major type of fast response?

A

Change in activity or function of enzymes or proteins in the cell

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

External signals induce what major type of slow response?

A

Change in the amounts of proteins by change in expression of genes

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

What is a long distance, long lasting type of signaling?

A

endocrine signaling
Signal -> bloodstream -> distant target cells
Freely diffusible signals

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What type of signaling acts locally, affects cells nearby (not as freely diffusable), and short lived?

A

Paracrine signaling

e.g. neurotransmitters

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

What type of signaling is released to themselves or release to cells of the same type?

A

Autocrine signaling
Cells secrete signal that feeds back and binds to a receptor on its won surface

E.g growth factor in cancer cells

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

What type of signaling does the immune cell elicit?

A

Direct cell signaling
Ag-presenting cell to T cells

*also known as juxtacrine signaling

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

What does acetylcholine do to heart muscle cells?

A

relax them

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

What does acetylcholine do to skeletal muscle cells?

A

contract them

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

What does acetylcholine do to salivary gland cells?

A

Cause them to secrete saliva

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

What are signaling cascade components?

A

signals, receptors, effectors

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

What can make up a cell signaling ligand?

A

proteins, small peptides, amino acid derivatives, hydrophobic molecules, steroid hormones like estrogen.

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

What are the main categories of cell signaling molecules?

A

small lipophilic molecules: steroid hormones

water soluble molecules- growth factors

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

What are two types of signaling module receptors?

A

intracellular receptors and cell surface receptors.

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

What is a specific type of intracellular receptors?

A

steroid receptor

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

What type of molecules can diffuse across the cytoplamic membrane and bind to intracellular receptors?

A

small hydrophobic signaling molecules

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What are most signaling molecules?

A

hydrophilic and require cell surface receptors

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What are intracellular ligands and signals?

A

VART

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

WHat are three main types of cell signaling receptors in the plasma membrane?

A

gated ion, G protein coupled receptors, enzyme coupled receptors

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Where are gated ion channels common?

A

nervous tissue

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What is special about GCPR?

A

7 pass transmembrane proteins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What does enzyme coupled receptor class include?

A

receptor tyrosine kinases

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What is one major class of surface receptors that mediate signals inside the cell?

A

GPCRs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

What type of receptors affect olfaction, sight and taste?

A

GPCRs

26
Q

What type of transmembrane receptors are targets of many drugs?

A

GPCRs

27
Q

What three parts is the G protein coupled receptors composed of?

A

extracellular domain- binds to ligand
transmembrane domain- anchors receptors
cytoplasmic domain- associated with G protieins

28
Q

What are heterotrimeric G proteins?

A

are guanine nucleotide-binding proteins that consist of three subunits designated αβ γ

29
Q

What have no instrinsic catalytic activity and regulated target enzymes?]?

A

g protein coupled receptors

30
Q

What is the GPCR activity cascade?

A 
GPCR----->
Trimeric G protein---->
effector enzyme, adenyl cyclase--->
2nd messenger, cAMP---->
Targets of 2nd messenger---->
Biological response
31
Q

What is GEF?

A

guanidine exchange factor

32
Q

What causes GTP to change to GDP?

A

hydrolysis

33
Q

What is the common subunit upstream of cAMP production?

A

Gsalpha

34
Q

What does cAMP activate?

A

cAMP- dependent protein kinase, PKA, 4 subunits

35
Q

What can active PKA do?

A

phosphorylate other proteins

36
Q

What are the 4 consequences of phosphorylation by PKA?

A
  1. form part of structure
  2. change enzymatic target
  3. change intracellular localization of target protein
  4. alterations in abundance of target proteins
37
Q

What does cholera cause you to do what?

A

pump a lot of water into your gut… lots of diahrea

38
Q

What does cholrea target?

A

toxin targets a G-protein

39
Q

How does cholera modify G proteins?

A

by keeping the G alpha in the GTP active form indefinitely… lots of cAMP…. lots of PKA… Lots of secretion of water
Continually pumping water and Cl out of the cells

40
Q

What is desensitization?

A

ability to turn off or reject the signal

can lead to cancer

41
Q

potentiate

A

turn up

42
Q

attenuate

A

turn down

43
Q

What happens when hormone levels drop?

A

decreased adenylyl cyclase activity…. decreased cAMP…

44
Q

What will remove cAMP/ cGMP?

A

phosphodiesterases

45
Q

How do you sequester the receptors?

A

endosomes

46
Q

How do you destroy receptors of the cell?

A

endosomes and lysososmes (proteases)

47
Q

What are G protein receptor kinases?

A

phosphorylate the receptor such that another protein called arrestin will bind to the 3rd intracellular loop and prevents Galpha from interacting with the third loop
- causing desensitiation of signal

48
Q

Phosphoplipase C cleaves PIP2 to produce what?

A

IP3 and DAG

49
Q

IP3 and DAG triggers?

A

release of Ca from endoplasmic reticulum

50
Q

What are the two types of secondary messangers

A

cAMP and Ca

51
Q

What type of enzyme coupled receptors do growth factors use?

A

tyrosine kinases

52
Q

What is the structure of tyrosine kinases?

A

single pass transmembrane domain

53
Q

What happens when a protein binds to a tyrosine kinase?

A

dimerization and then autophopshorylation occurs causing a scaffolding effect.

54
Q

What binds to the SH2 domain of Grb2?

A

RTK

55
Q

What does SH3 domain of Grb2 bind to?

A

prolines and SOS

56
Q

What is the first human oncogene?

A

Ras, plays crucial role in cell dividsion and a frequent mutation in cancer

57
Q

How many steps are involved to get to changes in protein activity in gene expression?

A

3 steps

58
Q

What is the MAP kinase pathway?

A

Grb2-Sos- RAS-RAF-Mek-Erk

59
Q

What seperates JAK STAT from tyrosine kinases?

A

More direct route, not using scaffolding

Goes straight to transcription regulation; however, lacks regulation

60
Q

What is the difference in serine threonine?

A

Uses serine threonine instead of tyronsine kinases… SMAD controls cell proliferation

Molecular Test III (7 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions