Brainscape's Knowledge GenomeTM

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


See full index

Foundations of Medicine > Holy Cell Biology > Flashcards

Holy Cell Biology Flashcards

Week 2

1
Q

What are glycolipids important for?

A

cell recognition and adhesion

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

In which leaflet are almost all phosphatidylethanolamine and phosphatidylserine located?

A

cytoplasmic leaflet

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

In which leaflet are phosphatidylcholine and sphingomyelin mostly found?

A

non cytosolic leaflet

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

Where is the glycocalyx and what is it used for?

A

inside lumen or outside cell, used for protection, identification, and adhesion

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

What are the main functions of the RER and SER?

A

RER: synthesize proteins, synthesize lipids
SER: synthesize lipids, metabolize and detoxify, regulate Ca2+

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

Where is N-linked glycosylation done?

A

In ER, sugar is attached to asparagine

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

What complex helps transport misfolded proteins into lumen for degradation?

A

sec61 translocator complex

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

What is cytochrome p450 used for in the SER?

A

detoxification

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

What are the cis and trans face of the Golgi body?

A 
cis = entry
trans = exit
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Where does O-linked glycosylation occur?

A

Golgi- adds oligosaccharides to proteoglycans

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

What 3 places does Golgi direct transport to?

A

lysosomes, secretory vesicles, plasma membrane

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

Where does Mannose-6 phosphate target to?

A

lysosomes, from golgi

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

What are lysosomes used for?

A

Digestive organelles filled with hydrolytic enzymes, pH about 5 (by proton pumps)

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

What does mitochondrial release of cytochrome C cause?

A

cell death

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

Where to mitochondrial localization sequences TOM, TIM, and OXA direct things?

A 
TOM= to outer mito membrane
TIM = to inner mito membrane
OXA = out of mito matrix
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What are peroxisomes?

A

single membrane bound organelles, do oxidation reactions, produce and decompose H2O2

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

How are microfilaments formed?

A

actin polymerization happens at + end

  • hydrolyzes ATP to ADP and becomes unstable
  • alpha beta actin dimers
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What do the Rho proteins (Rac, Rho, CDC42) do to actin?

A

Overall actin organization:
Rac- promotes gel like network, cell cortex
Rho- stress fibers, contractile bundle
CDC42- promotes tight parallel bundle

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

What are type 1 and type 2 myosin?

A

type 1 = short tail, can’t form filaments

type 2 = long tail, can form filaments (thick filaments)

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

What are microtubules?

A

heterodimers of alpha and beta tubulin

  • organize cytoplasm and intracellular transport
  • responsible for sperm mobility (flagella)
  • start with gamma tubulin at centrosome
  • grows - end to + end (also GTP to GDP decreases stability)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What does the drug taxol do?

A

stabilizes microtubules, arrests cells in metaphase and results in cell death
-chemo drug for cancer (inhibits tubulin depolymerization)

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

What do the 2 motor MAPs (microtubule associated proteins) dyneins and kinesins do?

A

Dyneins- move things toward MT - end

kinesins- move things toward MT + end

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

What does the drug colchicine do?

A

inhibits tubulin polymerization

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

What are intermediate filaments?

A

middle size, in both cytoplasm and nucleus

  • strengthen cytoplasm, nucleus, and cell to cell EC junctions
  • proteins are linear (rick in alpha helices)
  • 2 ends are structurally similiar
25
Q

How does phosphorylation affect intermediate filament growth?

A

low phosphorylation promotes polymerization

high levels phosphorylation promotes depolymerization

26
Q

What are sites of ribosomal RNA transcription and ribosomal unit assembly called?

A

nucleoli

27
Q

What is clathrin used for?

A

involved in endocytosis, assembles to form cage-like structures to deform membrane and begin vesicle formation

  • forms coated vesicles
  • Golgi to endosomes/ lysosomes
28
Q

What does the early endosome do?

A

receives pinocytotic vesicles

29
Q

What does the late endosome do?

A

located deeper in cytoplasm, digests internalized material

30
Q

Endosomes are formed from the fusion of..

A

vesicles from Golgi with hydrolytic enzymes and vesicles containing endocytosed cargo

31
Q

What does KDEL do?

A

identifies proteins that should stay in ER or come back to ER from Golgi

32
Q

What do coat proteins COP1 and COP2 do?

A

COP 2- coats ER vesicles that fuse with cis Golgi

COP 1- coat Golgi vesicles that fuse with ER

33
Q

What do SNARE proteins do?

A

help fuse PM of vesicle and correct target. V-SNARES on vesicle membrane correspond with t-SNARES on target organelle membrane

34
Q

What does cholesterol do in membranes?

A

inhibits phase transitions

35
Q

What are the 3 important lipids in membranes?

A

phospholipids, cholesterol, glycolipids

36
Q

Where are phosphoglycerides synthesized?

A

ER

37
Q

Where is sphingomyelin made?

A

Golgi apparatus

38
Q

Where are glycolipids made?

A

From sphingosine in Golgi apparatus

39
Q

What is the difference between flippases and scramblases?

A

flippases flip specific phospholipids between leaflets and scramblases are not specific

40
Q

What are lipid rafts?

A

specialized patches of lipids and proteins, asymmetry in PM, active in cell functioning and endocytosis

41
Q

What do cadherins do?

A

bind to proteins on adjacent cells, held together by calcium

42
Q

What are proteoglycans?

A

special class of very heavily glycosylated proteins

  • sugar chains are glycosaminoglycan (GAG) chains (repeating disaccharide units that are highly charged by sulfate (neg) groups)
  • O linked glycosylation
43
Q

What does accumulation of misfolded proteins trigger?

A

heat shock response (increased expression of chaperone proteins in cytoplasm)

44
Q

Where are phospholipids and cholesterol synthesized?

A

ER, active sites face cytoplasm but scramplases equilibrilate lipids between leaflets

45
Q

What is familial hypercholesterolemia (FH)?

A

deficit in an endocytotic pathway, cells don’t take up enough LDL from blood
-macrophages take up LDL and cause plaques

46
Q

What do GEF enzymes do?

A

convert GDP to GTP

47
Q

What are the 3 paths to lysosomes?

A

autophagy, phagocytosis, endocytosis

48
Q

What integral membrane protein is found in many uncoated vesicles?

A

caveolin

49
Q

what are peroxisomes used for?

A

detoxification reactions (ethanol to acetaldehyde), beta oxidation of FAs, formation of myelin phospholipids

50
Q

How are proteins destined for the nucleus targeted?

A

nuclear localization signal (NLS) which is a short region of AAs

51
Q

How is directionality of transport directed for nucleus?

A

Imported proteins: bind import receptors with GDP bound and dissociate in presence of GTP
Exported proteins: bind export receptors in presence of GTP and dissociate in presence of GDP

52
Q

What are Ran proteins?

A

G proteins that facilitate nuclear transport, Ran-GEF is concentrated in nucleus to make more Ran-GTP there

53
Q

What are the main functions of microfilaments?

A

support/ organize PM, cell shape, cell division, cell motility

54
Q

What are the main functions of microtubules?

A

organize cytoplasm, intracellular transport, cell division, cilia/flagella motility

55
Q

What are the main functions of intermediate filaments?

A

strengthen cytoplasm, support nucleus, epidermal appendages (hair and nails)- keratin

56
Q

What is the power stroke in contraction?

A

dissociation of ADP (not the hydrolysis step)

57
Q

What does integrin do?

A

links to EC matrix and provides traction to moving cell

58
Q

What is the centrosome?

A
  • a pair of centrioles and pericentriolar material

- used for microtubule nucleation and organization

Foundations of Medicine (7 decks)

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