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PROTEINS LIKE WATER, HMS YEAR 1
what is cytosol made of ?
concentrated aqueoous gel
function of plasma membrane
define boundaries, provide structure, protects the cell, transport
different components of cell plasma membrane
lipids, proteins, glycolipids, glycoproteins
name the main lipids in the bilayer and their property
phospholipids, cholesterol, glycolipids, —> has AMPHIPATHIC property
describe the self sealing lipid bilayer
hydrophobic tails fold to form balls so not exposed to water
bilayer (ball) w/ space in middle
what are the different movement of lipids in the bilayer?
flip flop = switch to different bilayer
rotation = rotate in same position
lateral = exchange w neighbour
name the factors that afect the fluidity of the membrane
double bonds = kink > more fluid at low temp
temp = low reduce fludity
cholesterol = low temp increase fluidity
what are the properties of cholesterol
polar head and non polar tail
change permeability and fluidity of membrane
improve membrane stability
what are the 2 diff types of proteins in membrane and describe their features
integral membrane protein = penetrate both membrane through lipid bilayer
peripheral = penetrate only one side of membrane
describe structure and function of integral membrane
multiple alpha helixes which has gap in middle
allow water soluble mol to cross membrane
name some function of membrane proteins
transporters and channels
anchors
receptors
enzymes
explain how the plasma membrane is reinforced
strengthened by cell cortex which has mesh like structure
cell cortex attached to membrane via transmembrane proteins in inner layer
explain how proteins create barriers
proteins move within bilayer so creat especialised areas
diff proteins on specific areas in bilayer > have specific functions in that area > each area has certain proteins zones with specialised fucntion
name the structure and function of carbohydrates
sugar attached to lipids or proteins
attract water molecules
help cell with protection, recognition and mobility
explain the fluid mosaic model
LIPID RAFTS > lipids cluster together on outer plasma membrane
tightly packed in rafts and influence fluididty
water mol pass through
what is the heterogenity of membranes ?
diff types of phospholipids only stay on one membrane which creates specialised sections and barriers
describe the structure and function of lysosomes
membrane enclosed organelle which contain digestive enzymes
remove damaged organelles and sent it back to be recycled
destroy viruses for cell
