Ch 5/6 Exam 2

Question 1

What are the functions of the plasma membrane?

Answer 1

Regulates passage of materials in and out of the cell
(helps maintain homeostasis)

Question 2

What is the Fluid-Mosaic Model?

Answer 2

The fluid mosaic model explains
membrane structure

Question 3

What are the components of the cell membrane?

Answer 3

phospholipids and proteins

Question 4

What is meant by semi-permeable?

Answer 4

allowing certain substances to pass through it but not others

Question 5

What is an integrated protein?

Answer 5

loosely associated with the bilayer

Question 6

What is a peripheral protein?

Answer 6

tightly bound to the bilayer

Question 7

Know the types in cell junctions and their function. (5)

Answer 7

-Tight junctions: seal membranes of adjacent animal cells together

-Gap junctions: form channels to communication between the
cytoplasms

-Adhering junctions: transmembrane
proteins that cement cells together

-Desmosomes: spot-weld adjacent animal cells together

-Plasmodesmata: channels connecting adjacent
plant cells. (certain
molecules and ions can pass from cell to cell)

Question 7

What is a concentration gradient?

Answer 7

If the particles are not evenly distributed, at least two regions exist: one with a higher concentration of particles and the other with a lower concentration. Such a difference in the concentration of a substance from one place to another

Question 8

What is simple diffusion?

Answer 8

solute molecules or ions move directly through the membrane down
their concentration gradient

Question 9

What is osmosis?

Answer 9

diffusion of water

Question 10

What is facilitated diffusion?

Answer 10

diffusion that requires protein carriers for molecules that are large

Question 11

What is a channel protein?

Answer 11

-form pores in membrane
* regulate passage of materials through the channels

Question 12

What is a carrier protein?

Answer 12

bind the molecule and change shape, moving the molecule across the membrane

Question 13

What is filtration?

Answer 13

the separation of solid matter from a liquid

Question 14

What is meant by active transport?

Answer 14

Movement against the concentration gradient (low to high)

Question 15

What are the types of active transport?

Answer 15

1. Exocytosis
2. Endocytosis

Question 16

What is hypotonic?

Answer 16

more surrounding fluid than the concentration within
the cell (shrink)

Question 17

What is hypertonic?

Answer 17

less surrounding fluid than the concentration within
the cell (swell)

Question 18

What is isotonic?

Answer 18

a fluid is of equal
solute concentration, or isotonic (no swell)

Question 19

What is hydrolysis?

Answer 19

Splitting bonds using water

Question 20

What is plasmolysis?

Answer 20

plasma membrane separates from the cell wall