Membranes Flashcards
What is the bilayer?
Layers of phospholipids with hydrophilic and hydrophobic regions
What is micelles?
Round circular layer of phospholipids
Where are intrinsic proteins found?
Across the whole membrane
What are glycoproteins?
Proteins attached to carbohydrate chains in membrane
What are channel proteins used for?
Passive movement of polar molecules down a concentration gradient by diffusion
What are carrier proteins used for?
Passive and active transport
Where are extrinsic proteins found?
Only on one side of the membrane
What is membrane fluidity important for?
Diffusion of substances
Cells to move and change shape
How does temperature effect membrane fluidity?
High temperature means the membrane is more permeable
What does alcohol and organic solvents do to membranes?
It dissolves them as they become more permeable
What factors effect diffusion?
Temperatures
Concentration gradient
What is ficks law?
The rate of diffusion is a given direction across an exchange surface
What is the equation for rate on membranes?
Rate = ( surface area × difference in concentration) ÷ membrane thickness
What is facilitated diffusion?
When ions and polar molecules move through carrier and Channel proteins down a concentration gradient
What is active transport?
Movement of molecules or ions across a membrane against the concentration gradient requiring ATP
