Membranes Flashcards
Roles of membranes
Regulates transport of minerals inside and outside cells
Separates contents from outside cell
Compartmentalisation
Cell recognition and cell signalling
Why are the membranes described as a fluid mosaic model
Bilayer of phospholipids = fluid
Various protein floating in it
Function of phospholipid
Allow lipid soluble substances to enter and leave
Give membrane fluidity
Prevent water soluble substances to enter and leave
What is the function of cholesterol
Stabilises cell membrane
Regulates fluidity
Reduces lateral movement of phospholipids
Membrane proteins
Structural support
Channel proteins
Carrier proteins
Receptors
Enzymes
Glycoproteins and glycolipids
Cell signalling
Cell recognition
Receptor
Help cells attach to one another form tissues
Membrane is particularly permeable because
Particles maybe too large to pass through protein channel
Maybe charged
Insoluble
How does cell signalling work
One cell communicate with another using molecules
What happens to plant cells when the water potential is low
Plasmolyed- cell membrane shrinks
Animal cells are …. if in a solution of very low water potential
Crenated
What happens animals and plant cells when the water potential is very high
ANIMAL- HAEMOLYSIS
PLANT - TURGID
Effect of high temperature on membrane proteins
Increase ke
H bonds and ionic bonds break
3d tertiary structure disrupted
Protein denatured
Permeability increases
Effect of high temperature on membrane phospholipids
Phospholipids gain ke
Phospholipids move more
Membrane fluidity increased
Membrane permeability increased
Effects of Ph on Membrane proteins
3d tertiary structure disrupted
H bond and ionic bonds break
Proteins denatured
Membrane permeability increased
Effect of organic solvents on membrane phospholipids lipids
Dissolve lipids
Membrane permeability increases
Membrane damages
