Cellular Membranes Flashcards
Phospholipids
Tiny blue spheres that make up a majority of the cell membrane
Peripheral membrane proteins
Proteins that sit on the outside or inside of the cellular membrane
Integral proteins
Sit inside the cellular membrane
What does the head of a phospholipid consist of?
Choline, phosphate, glycerol (polar)
(hydrophilic)
What does the tail of a phospholipid molecule consist of?
Fatty acid (nonpolar)(hydrophobic)
The two shapes phospholipids can arrange themselves into when placed in water
Micelles & liposomes
Micelle shape
Circle of phospholipids with a lack of water on the inside of the circle
Liposome shape
Bilayer of phospholipids (lipid bilayer)
Fluid mosaic model
Model of how proteins fit into the cell membrane
Difference between saturated and unsaturated lipid structure?
Unsaturated structure has a double bond that causes bending
How does saturation within phospholipids affect membrane fluidity?
Fewer unsaturated fatty acids means lower permeability within the membrane (less fluid going through the membrane)
What does cholesterol do within cell membranes?
Decrease membrane permeability
What role does temperature play within a cell membrane?
The higher the temperature, the higher the permeability of a cell membrane
The head of a phospholipid is
charged
Cells need to maintain a
Semi permeable membrane
In order to pass through a cell membrane, something must be
Small and nonpolar or partial charge
Solutes vs solvents
Solutes are particles
Solvents are the liquid in which they are encased
Brownian motion
The random movement of particles suspended in a fluid (liquid or gas)
Larger particles can be moved by…
Light, fast-moving molecules
Diffusion
The movement of something from an area of high concentration to low concentration
When does diffusion stop?
When we hit equilibrium
Equilibrium
An equal concentration of molecules on either side of the membrane
Net movement
The direction the majority of the molecules initially travel
Movement
Molecules continue to pass through the membrane in random fashion (but equal)
Diffusion of water is called…
Osmosis
Tonicity
The solute concentration of a solution as compared to another solution
Hypertonic
Solution with a higher solute concentration
Hypotonic
Solute concentration inside the cell is higher than outside the cell
What will cause a cell to burst?
An extreme net movement of water into the cell
What will cause a cell to shrink?
A large net flow of water out of the cell
Isotonic
When two solutions have an equal concentration in and outside of the cell
