Cell Membrane Flashcards
What is the name given to the cell membranes structure?
The fluid mosaic model
What’s the cell membrane composed of?
Lipids (Phospholipids) proteins and carbohydrates
What is the phospholipid layer called?
Bilayer - it’s fluid because it’s constantly moving
What are phospholipids heads and tails?
Tails - hydrophobic (attracts water) made of 2 fatty acids
Heads - hydrophobic (repels water) and contains the phosphate group
Where do the hydrophilic heads and hydrophobic tails place themselves in the bilayer?
Heads fave out towards the water either side of membrane and tails are ok inside of membrane making the bilayer hydrophobic (membrane doesn’t allow water soluble substances through it)
Where are proteins placed in the bilayer?
Scattered throughout it
What do some other rotenone have attached to them?
Polysaccharide chain - glycoproteins
What do some lipids have attached to them?
Polysaccharide chain - glycolipids
What is cholesterol, where is it found in the membrane and what does this then do?
A type of lipid
Fits in Between phospholipids
Makes membrane more rigid
What does the partially permeable membrane allow it to do?
Let small molecules move through gaps between phospholipids but large molecules can only pass through special membrane proteins called channel proteins
What is the cell membranes structure ‘known as’ ?
Fluid mosaic model
What are the 4 molecules that compose a cell membrane?
Lipids
Phospholipids
Proteins
Carbohydrates
What is the fluid mosaic model?
It was used to describe the arrangements of molecules in the membrane
What do the phospholipid molecules form in the membrane?
A bilayer
What are phospholipid molecules? What do they contain?
They have a hydrophilic head (contains the phosphate group)
They have a hydrophobic tail (made of 2 fatty acids)
How are the phospholipid molecules arranged in the membrane?
Hydrophilic head fave out towards the water on either side of the membrane
Hydrophobia tails are on the inside making the centre of the bilayer hydrophobic
MEMBRANE DOESN’T ALLOW WATER SOLUBLE SUBSTANCES (ions) THROUGH IT
Where are proteins located in the membrane?
They’re scattered through the bolster like tiles
As the bolster is fluid proteins can move around wishing it
Some proteins have a polysaccharide chain attached - glycoproteins
What are lipids and what do they have attached to them?
A polysaccharide chain attached - glycolipids
What’s cholesterol and where is it in the membrane?
A type of lipid and it fits between phospholipids forming bonds with them.
This makes the membrane more rigid
How is the membrane partially permeable?
Small molecules can move through gaps between the phospholipids but large molecules and ions can only pass through special membrane proteins called channel proteins and carrier proteins
