Factors affecting membrane structure and permeability Flashcards
What does the increase in temperature do to molecules?
Increase their kinetic energy.
What happens to saturated fatty acids when the temperature drops?
They become compressed.
How do unsaturated fatty acids assist in the maintenance of membrane fluidity when the temperature lowers?
The kinks in their tails push adjacent phospholipids away.
What determines the fluidity of the membrane at cold temperatures?
The proportions of unsaturated and saturated fatty acids.
How does cholesterol maintain fluidity in cold temperatures?
It buffers the effect by preventing the phospholipid molecules from packing together too closely.
What happens to phospholipids when temperatures increase?
They acquire more kinetic energy and move around more, in a random way.
What happens to the permeability of the membrane in increased temperatures?
It increases.
How does an increase in temperature affect membrane-embedded proteins?
It affects the way they are positioned and may function.
How does an increase in membrane fluidity affect phagocytosis?
It affects the infolding of the plasma membranes.
Why is cell signalling effected by an increase in temperature?
It affects the way the membrane is able to move during exocytosis. Changing the ability of cells to signal to other cells by releasing chemicals.
What happens to proteins in high temperature?
Their atoms vibrate causing the hydrogen bonds to break resulting in them unfolding.
If proteins in cells begin to denature why does the cell membrane begin to collapse?
The proteins embedded in the membrane and the proteins that make up the cytoskeleton hold the membrane in place. When they begin to denature the structure of the membrane begins to fail.
Why do organic solvents have an affect on cell membranes?
They dissolve lipids.
