Chapter 5

Question 0

__________ is the main energy carrier in all living cells.

Answer 0

Adenosine triphosphate

Question 1

_____ store and retrieve energy when they convert one molecule to another.

Answer 1

Cells

Question 2

JOBS OF THE PLASMA MEMBRANE ARE TO….

Answer 2

• Isolate the cytoplasm from the external environment
• Regulate the exchange of substances
• Communicate with other cells
• Semi-permeable
• Protects

Question 3

The plasma membrane is composed of how many layers?

Answer 3

2 (bilayer)

Question 4

Composed of ______ molecules

Answer 4

Phospholipid

Question 5

Phosphate groups are _____ in water and are _____.

Answer 5

Soluble, polar

Question 6

“Water loving”

Answer 6

Hydrophilic

Question 7

“Water hating”

Answer 7

Hydrophobic

Question 8

Fatty acid chains are _____ in water because they are _______.

Answer 8

Insoluble, nonpolar

Question 9

What is the fluid mosaic model?

Answer 9

Property of the plasma membrane where in many similar molecules are free to move sideways within the lipid bilayer.

Question 10

_______ molecules embedded in the membrane makes it stronger and less fluid. It also prevents the fatty acid chains from sticking together.

Answer 10

Cholesterol

Question 11

Regulate movement of particles/substance

Answer 11

Transport proteins

Question 12

Form small openings for molecules to diffuse through

Answer 12

Channel proteins

Question 13

Binding site on protein surface “grabs” certain molecules and pulls them into the cell.

Answer 13

Carrier proteins

Question 14

Similar to carrier proteins, not always “open”

Answer 14

Gated channels

Question 15

Molecular triggers that set off cell responses (such as release of hormones or opening proteins)

Answer 15

Receptor proteins

Question 16

______ determines how substances move within cells and their membranes

Answer 16

Diffusion

Question 17

Movement of particles across membranes by diffusion. Requires no energy.

Answer 17

Passive transport

Question 18

Movement of particles across membranes from areas of lower concentrations (the environment) to higher concentrations (in the cell); moves against a concentration gradient. Requires energy.

Answer 18

Active transport

Question 19

EX of passive transport

Answer 19

Diffusion, osmosis, facilitated diffusion

Question 20

EX of active transport

Answer 20

Endocytosis, exocytosis, sodium potassium pump

Question 21

Process by which a cell surrounds & takes in material from its environment.

Answer 21

Endocytosis

Question 22

Expulsion or secretion of materials from a cell.

Answer 22

Exocytosis

Question 23

Is the diffusion of water molecules through a selectively permeable membrane from an area of higher water concentration to an area of lower water concentration

Answer 23

Osmosis

Question 24

Is when the concentration of dissolved substances (solute) in the solution is the same as the concentration of dissolved substances inside the cell. Cells in an isotonic solution do NOT experience osmosis and they retain their normal shape.

Answer 24

Isotonic solution