Cell Membranes Flashcards
Describe the roles of membranes
Separates cell from environment Controls entry of molecules Facilitated diffusion Active transport Exocytosis Cell recognition Compartmentalisation Separates DNA
Actors affecting membrane structure
Temperature
Solvents
How does temperature affect membranes
KE increases
Temporary gaps in membrane, making it more fluid as it vibrates and permeable
Eventually breaks down
Carrier and channel proteins break down
How do solvents affect membranes
Polar solvent is needed to form a bilayer
Organic solvents dissolve membranes as it makes it fluid and more permeable
What is the cell membrane made up of
Cholesterol Protein (channel) Phospholipid Glycoproteins Glycolipids
What does cholesterol do
Regulates fluidity of membrane
Stabilises movement
Restricts movement of membrane
Storage
What do protein channels do
Allow passage of polar substances
Prevents passage of lipid soluble substances
What do phospholipids do
Allow lipid soluble substances through
hydrophobic and hydrophilic
What do glycoproteins and glycolipids do
Cell attachment
Cell recognition
Cell signalling
