Plasma Membrane Flashcards
(17 cards)
PM has NO _______________ bonds
NO TRANS DOUBLE BONDS IN PM
PM composed of
Lipids
Sterols
Proteins
PM functionality based on
Length and saturation of fatty acid
Hydrophilic head group composition
Phosphoglycerides
Glycerol (3C) base w 2 fatty acid chains
Common= both linked via ester
Plasmogen= 1 linked via ester linkage to glycerol
3rdC of glycerol= polar head group
Variable head group PE-NH3 PC-NCH3 PS-carboxyl PI- ring
Sphingolipids
Base= sphingosine - amino alcohol w 1 fatty acid gain
Link additional fatty acid chain via amide bond
Glycolipid= sugar head group
Variable head groups
SM-NCH3
GlcCer- ring
Sterol
4 ring hydrocarbon
Cholesterol
Intercalate between phospholipids and align polar group with polar head
Lipid composition can affect thickness and curvature of PM
Phospholipids can be what type if membrane lipids?
Phosphoglycerides or sphingolipids
Properties of bio membranes
Fluid
Closed compartments
Semi-permeable
Asymmetric
FRAP assay
Fluorescence recovery after photo bleaching assay
- Label membrane proteins w fluorescent reagent
- Bleach portion w laser
- At a later time pt, measure amount of fluorescence recovered in that area
%fluorescence recovered proportional to fluidity
Carbohydrates on what leaflet of PM?
Exoplasmic
Not cytosolic
Therefore, asymmetry
Passive diffusion does not require
A transmembrane protein
Primary Active transport P class pumps pump
H+
K+
Na+
Ca2+
Primary Active transport V and F class pumps pump
H+ only
Primary Active transport
ABC type pumps pump
Many small molecules
Secondary active transport
No E required
Requires primary active transport, uses conc gradient created by it
Voltage gates channel
Change in membrane potential opens channel
E.g. Ca2+ release channel on sarcoplasmic reticulum
Facilitated transport (driven by conc gradient) Gates
Facilitated transport-types
Pores
Channels
Gates
Uniporters
