BIO 101 Final Chapter 3

Question 1

Phospholipids are the major components of membranes

Answer 1

hydrophilic head =’s phosphate

hydrophobic tails = 2 fatty acid tails

Question 2

Cellular Membranes

Answer 2

protect inner contents of animal cells from its external environment

allows a cell to differ structurally and biochemically from its surroundings.

Question 3

Passive transport: no energy is required

a) diffusion
b) osmosis

Answer 3

a) diffusion is when a high concentration of a substance in one area migrates spontaneously to an area where the substance is in low conc.
high conc.-> low conc.

b) osmosis = diffusion of H2O across a membrane

h2o moves from an area of high water conc. to an area of low water conc.

Passive transport of water across a membrane from a low solute conc. to a high-solute conc.

more specialized than diffusion: movement of water only

Question 4

Bulk transport; Endocytosis

Answer 4

endcytosis: cells engulf large particles (food,bacteria) within their plasma membranes; involves vesicles.