Cell Membrane Dynamics (ch3) Flashcards
(73 cards)
1
Q
Parts of the cell
A
Nucleus, Cytoplasm, Plasma membrane
2
Q
Function of plasma membrane
A
- provides flexible support
- Physical isolation (seperates ICF and ECF)
- Regulates flow of material b/w cells and external environment
- communication b/w cells
3
Q
fluid mosaic model
A
movement of fluid lipids and contains different proteins
4
Q
amphipathic molecules
A
having both polar and non polar parts
5
Q
hydrophilic
A
interacts with water
6
Q
hydrophobic
A
does not interact with water
7
Q
types of lipid molecules
A
phospholipids, cholesterol, glycolipids
8
Q
Phospholipid head
A
polar, hydrophilic, contains choline and phosphate
9
Q
Phospholipid tail
A
nonpolar, hydrophobic, contains fatty acid chain
10
Q
what connects the tail end and head end
A
glycerol backbone
11
Q
what % of lipid bilayer is phospholipid
A
75%
12
Q
what % of lipid bilayer is cholesterol
A
20%
13
Q
Function of cholesterol
A
makes membrane impermeable to small water molecules, keeps membranes flexible
14
Q
cholesterol is a ________?
A
steroid
15
Q
Cholesterol head end
A
polar, hydrophilic, contains hydroxyl groups
16
Q
Cholesterol tail end
A
nonpolar, hydrophobic
17
Q
what % of lipid bilayers is glycolipids
A
5%
18
Q
What is a glycolipid
A
sugar attached to fat, only appears on the external surface, creates a asymmetric bilayer
19
Q
Glycolipid head end
A
polar, hydrophilic, contain sugar and glycerol
20
Q
glycolipid tail end
A
nonpolar, hydrophobic, contains fatty acids
21
Q
sugar bound to lipid
A
glycolipid
22
Q
sugar bound to protein
A
glycoprotein
23
Q
glycocalyx
A
sticky layer
24
Q
Cell membrane consist of
A
cholesterol, phospholipids, carbohydrates, proteins
25
cholesterol and phospholipids form...
lipid bilayer
26
Phospholipids and carbohydrates form...,
glycolipids
27
carbohydrates and proteins form...
glycoproteins
28
Function of lipid bilayer
barrier between cytosol and external environment
29
function of glycolipids and glycoproteins
provides stability, cell recognition, and immune response for cell membrane
30
classes of protein membranes
integral proteins and peripheral proteins
31
integral proteins
lie within the membrane, key part of cell membrane
32
peripheral proteins
bound to inner or outer surface of membrane, can be removed
33
Channel proteins
will always have clear access, the pore allows ions to flow through,
34
Carrier proteins
one end of protein is always closed, transports substance by changing shape, aka as transporter
35
Receptor proteins
bind and respond to ions, will trigger other events, alters cells function
36
Enzyme
catalyze reactions takes place on external surface or inside membrane
37
Anchoring proteins
links cells togethers, provides structural stability and shape for cell, aka as structural & linker protein
38
Recognition proteins
distinguishes your cells from somebody else's
39
membrane fluidity
movement of lipids & proteins
40
movement of lipids and proteins
mobile in their own half of bilayer
41
movement of phospholipds
fast, 10 million times/sec, flip flopping = rare
42
concentration gradient
difference in concentration of chemicals on different sides if membrane
43
electrical gradient
difference in concentration of ions between one side of the plasma membrane and the other
44
electrochemical gradient
made from concentration gradient and electrical gradient
45
General properties of diffusion
1. Diffusion is a ________ process.
2. molecules move from a _____________.
3. Net movement of molecules occurs until _________,
4. Diffusion is ______ over short distances and _______ over long distance
5. Diffusion is directly related to _______
6. Diffusion rate is inversely related to _______
7. Diffusion can take place in an _____ or _______
1. passive process
2. a higher concentration to an area of lower concentration
3. concentration is equal everywhere
4. rapid, slower
5. temperature
6. molecular weight and size
7. open system, across a partition that separates two compartments.
46
Primary influences of diffusion
concentration gradient, lipid solubility of diffusing substance, mass of the diffusing substance
47
Simple diffusion
- molecules can mix with polar heads
- lipid soluble non polar molecules can dissolve through membrane
48
Types of facilitated diffusion
Channel-mediated & Carrier Mediated
49
Channel Mediated Facilitated diffusion
targets small ions and water, act like door across membrane
50
Carrier-Mediated Facilitated Diffusion
Targets larger water soluble compounds, acts as revolving door
51
Osmosis
takes place in selective permeable membrane that is permeable to to water, movement of water
52
Water flow in osmosis
water flows to the solution that has higher concentration
53
osmotic pressure
hydrostatic pressure required to stop osmotic flow
54
isomatic solution
contain equal number of particles per volume
55
Hyperosmotic solution
If solution A has a higher osmolarity than solution B
56
Hyposmotic
If solution B has a lower osmolarity than solution A
57
normal osmolarity of human body
300
58
Tonicity
how a solution affects cell volume
59
isotonic
does not cause osmotic flow
60
hypotonic
cell gains water
61
hypertonic
cell loses water
62
passive process
move down the concentration gradient
63
Active process
requires energy to move against concentration gradient
- exhibits and transport maximum and saturation
64
primary active transport
requires ATP to transport substances, aka as pumps
65
Secondary Active transport
doesnt rely on ATP, uses energy from concentration gradient
66
Vesicular transport
substances move in vesicles, performs bulk transport, requires ATP
67
types of endocytosis
receptor-mediated endocytosis, phagocytosis, bulk phase endocytosis
68
Receptor-mediated Endocytosis
- ions bind to clathrin-coated pits
- clathrin removed and returns to membrane
- transport mechanism for protein, hormones, plasma proteins
69
Phagocytes
Performed by macrophages and neutrophils
- pathogens bind onto membrane receptors
- phagosome fuses with lysosomes
70
Bulk phase endocytosis or pinocytosis
- non selective process
- transports fluid content
- not well understood
71
exocytosis
- goes everywehre
- release of neurotransmitters by neurons
- insertion og glucose transporters or water channels
72
transcytosis
- combination of endocytosis and exocytosis
- makes it possible for large proteins to move across epithelium and remain intact
73
Caveolae
-"little caves"
- used to concentrate receptor- bound molecules
