3B

Question 1

plasma membrane

Answer 1

the phospholipid bilayer and embedded proteins which separate the intracellular environment from the extracellular environment. Also known as cell membrane

Question 2

selective permeability

Answer 2

a property of cell membranes that ensures only specific substances pass across them. Also known as semipermeable

Question 3

cytosol

Answer 3

the aqueous fluid that surrounds the organelles inside a cell

Question 4

passive transport

Answer 4

the movement of molecules through a semipermeable membrane and down the concentration gradient, without an input of energy

Question 5

active transport

Answer 5

movement of molecules across a semipermeable membrane that requires energy

Question 6

diffusion

Answer 6

the passive movement of molecules from areas of high concentration to areas of low concentration (down the concentration gradient)

Question 7

concentration gradient

Answer 7

the difference in solute concentration between two adjacent areas

Question 8

kinetic energy

Answer 8

the energy a particle or body possesses due to motion

Question 9

solute

Answer 9

a substance dissolved in the solvent

Question 10

solvent

Answer 10

a liquid in which a solute is dissolved, forming a solution

Question 11

nonpolar

Answer 11

describes a molecule without a clearly positive or negative end. These tend to be hydrophobic

Question 12

hydrophobic

Answer 12

having a tendency to repel and be insoluble in water

Question 12

hydrophilic

Answer 12

having a tendency to be attracted to and dissolve in water

Question 13

polar

Answer 13

describes a molecule with both a positive end and a negative end. These tend to be hydrophilic

Question 14

facilitated diffusion

Answer 14

a type of passive transport where molecules move through a phospholipid bilayer with the aid of a membrane protein

Question 15

protein channel

Answer 15

a transmembrane protein pore in a phospholipid bilayer that selectively enables the transport of large or polar molecules

Question 15

carrier protein

Answer 15

a membrane protein that undergoes conformational change to transport molecules across a membrane

Question 16

conformational change

Answer 16

a change in the three-dimensional shape of macromolecules such as proteins

Question 17

osmosis

Answer 17

the passive transport of a solvent (typically water) through a semipermeable membrane from a region of low solute (high solvent) to a region of high solute (low solvent)

Question 18

tonicity

Answer 18

a measure of the relative concentration of solutes on either side of a semipermeable membrane, described as hypertonic, hypotonic, or isotonic

Question 19

hypertonic

Answer 19

describes a solution with a higher solute concentration when compared to another solution

Question 20

isotonic

Answer 20

describes a solution with the same solute concentration as another solution

Question 21

hypotonic

Answer 21

describes a solution with a lower solute concentration when compared to another solution

Question 22

turgid

Answer 22

describes plant cells that are swollen and firm from water uptake

Question 23

plasmolysed

Answer 23

describes plant cells with weak and sagging plasma membranes from water loss

Question 24

lyse

Answer 24

to cause a cell plasma membrane to burst or break