fators affecting permeability

What are the 2 factors that affect permeability

Temperature and solvents

What is a solvent

A iquid that had the ability to dissolve substances

What are examples of organic or non-polar solvents

Ethanol and Methanol

What happens when cells are placed in a solvent

The phospholipids dissolve, so the membrane becomes more fluid/permeable

What does increasing the conc of true solvent do to the permeability

It increases the permeabilty

How do you get drunk

The permeability of the cell membrane of a neuron increases, more sodium and potassium ions pass through the channel proteins and this slows the nervous system down

What happens to cells at high temperatures (40+)

lots of kinetic energy, more movement so more permeability. Too much movement makes the bilayer break down and channel proteins break down, allowing other molecules to diffuse in/out

What happens to cells at normal temperatures (0-40)

As temp increases, so does kinetic energy, so the bilayer is more fluid/permeable

What happens to cells at low temperatures (below 0)

They have no kinetic energy, so the permeability is 0

If a frozen cell is thawed, what happens

Water expands when frozen pressuring the membrane, when frozen water forms ice crystals that’s pierce the membrane and leaves holes when melted