Lab chapter 2: Osmosis/Diffusion

Question 1

eukaryotic cells are covered by a ____

Answer 1

cell/plasma membrane

Question 2

Name the four functions of the cell membrane

Answer 2

1. Barrier
2. Transport
3. Organization
4. Communication
5. Recognition

Question 3

Describe how the cell membrane “barrier” function works

Answer 3

Lipad bilayer blocks the entry into cell of most substances except water, glycerol, and small lipid-soluble molecules

Question 4

Describe the cell membrane “transport” function

Answer 4

Cell takes up metabolites and eliminates waste products
Molecules move from high to low concentrations

Question 5

What is facilitated diffusion?

Answer 5

substances move through protein channel down their concentration gradients. Passive

Question 6

What is active transport?

Answer 6

membrane proteins move against concentration gradient and requires energy

Question 7

Describe the “organization” function of cell membranes

Answer 7

membranes organize enzymes and electron chains so cell processes are efficient

Question 8

Describe the “communication” process of cell membrane

Answer 8

Hormones bind to receptors on cell surface to trigger reactions

Question 9

Describe the ‘recognition” function of cell membranes

Answer 9

Molecules on surface allow organism between its own cells and foreign cells, basis of immune system

Question 10

Define diffusion

Answer 10

random movement of molecules that occurs in a fluid or a gas, or even in a solid. Movement from high to low concentration.

Question 11

What is osmosis?

Answer 11

Movement of water through semipermeable membrane in response to different concentration of water on two sides of a membrane.

Question 12

Water will flow from a ___ solute concentration to a _____ solute concentration

Answer 12

low to high