Phospholipids are the most

Abundant lipid in the plasma membrane

Phospholipids are amphipathic molecules, containing?

hydrophobic and hydrophilic regions.

What does the fluid mosaic model state?

that a membrane is a fluid structure with a "mosaic of various proteins embedded in it.

Cellular Membranes are made of what?

Proteins and lipids

Phospholipids in the plasma membrane can move

within the bilayer

Most of the lipids and some proteins

drift laterally

Rarely does a molecule

flip-flop transversely across the membrane.

As temperatures cool,membranes

switch from a fluid state to a solid state

What depends on the types of lipids?

the temp at which a membrane solidifies

Membranes rich in unsaturated fatty acids are?

are more fluid than those rich in saturated fatty acids

Membranes must be what to function properly?

Fluid (usually about as fluid as salad oil)

The steroid cholesterol has different effects on what?

Membrane fluidity at different temperatures

At warm temperatures (such as 37c)

cholesterol restrains movement of phospholipids

At cool temperature it maintains fluidity by

preventing tight packing