chapter 3

Question 1

the cell membrane separates cell from environment

Answer 1

1. physical isolation
2. regulation of exchange w/ the environment
3. communication btw the cell and its environment
4. structural support
   > secretion - cell releases substance into extracellular space

Question 2

biphospholipid layer

Answer 2

• in most membranes

Question 2

membranes are mostly lipid and protein

Answer 2

fluid mosaic model - the structure of the plasma membrane as a mosaic of components —including phospholipids, cholesterol, proteins, and carbohydrates—that gives the membrane a fluid character