Brainscape's Knowledge GenomeTM

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


See full index

Cell Biololgy and Histology BAM > Lecture 3 > Flashcards

Lecture 3 Flashcards

0
Q

Mreb

A
  • prokaryotic ancestor of actin

- give rod-shaped bacteria structure

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

Microfilaments

A
  • made up of actin (alpha muscle, beta/gamma non)
  • abundant in all tpyes of eukaryotic cells
  • 4 muscle, 2 non
  • actin is highly conserved
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Cytochalasins

A
  • bind to barbed end
  • block elongation
  • can inhibit mitosis
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Phalloidin

A
  • prevents dissociation

- can be labeled with fluorescent dyes

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

Spectrin

A
  • found in RBCs
  • binds cortical cytoskeleton to plasma membrane
  • ghost RBCs after bursting
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Dstrophin

A
  • binds cortical cytoskeleton to plasma membrane

- muscular dystrophy gets name from this

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

Villin and Fimbrin

A

-cross-links in microvilli

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

Caalmodulin and Myosin 1

A

-cross-links actin to plasma membrane in microvilli

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

alpha-actinin

A
  • cross-links stress fibers and connects actin to protein-plasma membrane copes
  • adaptor for integrins to interact with F-actin
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Filamin

A
  • cross-links actin at wide angles to form screen-like gels
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Thymosin

A
  • controls treadmilling

- captures actin monomers and prevents from being polyerized

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

Profilin

A
  • binds to actin monomers, prevents polymerization
  • controls treadmilling
  • facilitates exchange of bound ADP for ATP
  • *only ATP-actin monomers can assemble into F-actin
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Gelsolin

A
  • controls treadmilling
  • destabilizes F-actin and caps filaments, prevents loss and addition of G-actin
  • in presence of Ca, fragments actin filament and remains bound to plus end
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Cofilin

A
  • controls tread

- triggers depolymerization of ADP-bound actin at minus end

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

Arp 2/3

A
  • initiates growth of F-actin fro sides of existing filament
  • causes branching
  • nucleation (3 actin monomers coming together) is rate-limiting
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Formin

A
  • and Arp 2/3 complex determine where filament are formed
  • large dimers that bind initial monomer, and move along the growing filament
  • nucleate long unbranched actin filaments, many stabilized by tropomyosin
16
Q

Laatrunculins

A
  • bind to G-actin and induce F-actin depolymerization

- non native proteins, used in research to break down filaments

17
Q

Parallel Bundles

A
  • closely spaced actin filaments aligned in parallel

- barbed ends adjacent to plasma membrane

18
Q

Contractile Bundles

A
  • more widely-spaced filaments, cross-linked by alpha-actinin
  • allows motor protein myosin to interact with actin
19
Q

Intermediate Filaments

A
  • abundant in cells subject to mechanical stress
  • provide tensile strength to cells such as neurons and muscle
  • strengthen epithelial cells such as desmo and hemi
  • common monomer consisting of central a-helix rod flanked by head and tail domains
20
Q

Intermediate Assembly

A
  • 2 antiparallel dimers form staggered tetramer
  • form spontaneously, doesn’t require ATP
  • formed by poly of long, rodlike proteins
  • repeated AA segents (heptads)
21
Q

Intermediate Filament Associated Proteins (IFAPs)

A
  • stabilize filament
  • may cap to prevent further elongation
  • filaggrin, epinemin, paranemin, plectin, synemin
22
Q

Intermediate Filament Types

A
  • Type I: acidic keratins, associaed with plaques of desmo and hemi
  • Type II: neutral to basic keratins
  • Type IV: neurofilaments, axons and dendrites
  • Type V: nuclear lamins, mechanical support for nuclear envelope
  • Type VI: nestin, associated with CNS stem cells
23
Q

Microtulues

A
  • thick, composed of tubulin dimers
  • consist of 13 protofilaments
  • plus end grows more rapidly in presence of low Ca
24
Q

Factors Inhibiting Microtubule Polymerization

A
  • colchicines, used to create karyotype
  • colcemid
  • vincristine and vinblastin, anti-cancer
  • taxol stabilize
25
Q

Cilium Structure

A
  • 9 peripheral doublets + central pair of microtubules

- each doublet has alpha tubule (13 protofilaments) and beta (10-11)

26
Q

Fatty Acid Characteristics

A
  • long-chain pack well together and limit movment
  • short are more limited but create spaces which other chains can move
  • saturated has no double bonds, max H+
27
Q

Outer Leaflet of Phospholipid bilayer

A
  • Cholesterol
  • phosphatidylcholine
  • sphingomyelin
28
Q

Inner Leaflet of Phospholipid bilayer

A
  • cholesterol, phosphatidylethanolamine, phosphatidylserine (- charge)
  • phosphatidylinositol, - charge, important in cell signaling, only in inner
29
Q

Glycolipids

A

-outer leaflet with carbohydrate portion facing extracellular, forms glycocalyx

30
Q

Cholesterol

A
  • High temps, interfers with FA chain movement, makes membrane less fluid, reduced permeability to small molecules
  • low temps, prevents membranes form freezing
31
Q

Glycocalyx

A
  • not integral part of membrane

- carb coat composed of carb portions of glycolipids and glycoproteins

32
Q

Lipid Rafts

A
  • small patches of cholesterol and sphingolipids

- no proteins, smooth surface

33
Q

Peripheral Proteins

A

-can be removed by altering pH or ionic content of environment

34
Q

Integral Proteins

A
  • Embedded, extracellular portion typically glycolsylated

- can only be removed by detergents

35
Q

Transmembrane Proteins

A
  • integral that pass completely through both layers
  • channel or transporter proteins
  • 1 hydrophobic and 2 philic domains
  • membrane-spanning portions usually a helix with 20-25 hydrophobic AA (glycophorin, band 3 anion tranporter for Cl ions)
36
Q

Single Pass Transmembrane Proteins

A
  • single hydrophobic domain passes through layer only once
  • enzyme-like receptrors (receptor tyrosine kinases)
  • glycophorin (RBC membranes)
37
Q

Multiple-pass Transmembrane Proteins

A
  • use two or more hydrophobic domains
  • activated by add of phosphate
  • G-protein-linked receptors (7 trans domains)
  • Large transporter and channel proteins (porin has 12 trans domains as does glucose)

Cell Biololgy and Histology BAM (11 decks)

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