Ap Bio Vocab Ch 7

Front 1

Selective Permeability

Back 1

A membrane that will allow certain molecules or ions to pass through it by diffusion and occasionally specialized "facilitated diffusion".

Front 2

Diffusion

Back 2

The process in which there is movement of a substance from an area of high concentration of that substance to an area of lower concentration.

Front 3

Hypertonic

Back 3

In comparing two solutions, refering to the one with a greater solute concentration.

Front 4

Osmosis

Back 4

Diffusion of molecules through a semipermeable membrane from a place of higher concentration to a place of lower concentration until the concentration on both sides is equal.

Front 5

Plasmolysis

Back 5

The process in plant cells where the plasma membrane pulls away from the cell wall due to the loss of water through osmosis.

Front 6

Gated Channels

Back 6

A protein channel in a cell membrane that opens or closes in response to a particular stimulus.

Front 7

Cotransport

Back 7

Also known as coupled transport, refers to the simultaneous or sequential passive transfer of molecules or ions across biological membranes in a fixed ratio.

Front 8

Amphipathic

Back 8

A molecule having both hydrophilic and hydrophobic parts.

Front 9

Passive Transport

Back 9

Transport of a substance across a cell membrane by diffusion; expenditure of energy is not required.

Front 10

Hypotonic

Back 10

In comparing two solutions, referring to the one with a lower solute concentration.

Front 11

Osmoregulation

Back 11

The maintenance of constant osmotic pressure in the fluids of an organism by the control of water and salt concentrations.

Front 12

Crenate

Back 12

A leaf having a round-toothed or scalloped edge.

Front 13

Active Transport

Back 13

The movement of ions or molecules across a cell membrane into a region of higher concentration, assisted by enzymes and requiring energy.

Front 14

Exocytosis

Back 14

A process by which the contents of a cell vacuole are released to the exterior through fusion of the vacuole membrane with the cell membrane.

Front 15

Pinocytosis

Back 15

The ingestion of liquid into a cell by the budding of small vesicles from the cell membrane.

Front 16

Fluid Mosaic Model

Back 16

A model of membrane structure in which proteins are inserted in a fluid phospholipid bilayer.

Front 17

Concentration Gradient

Back 17

The increase or decrease in the density of a chemical substance in an area.

Front 18

Isotonic

Back 18

Having the same solute concentration as another solution.

Front 19

Turgid

Back 19

The main pressure of the cell contents against the cell wall in plant cells and bacteria cells, determined by the water content of the vacuole, resulting from osmotic pressure.

Front 20

Facilitated Diffusion

Back 20

The movement of molecules across a membrane from a region of high concentration to a region of low concentration that is assisted by proteins.

Front 21

Sodium-Potassium Pump

Back 21

A special transport protein that transports sodium out of the cell and potassium into the cell against their concentration gradients.

Front 22

Endocytosis

Back 22

The process by which cells absorb molecules (such as proteins) from outside the cell by engulfing them with their plasma membrane.

Front 23

Receptor-Mediated Endocytosis

Back 23

A process by which cells internalize molecules by the inward budding of plasma membrane vesicles containing proteins with receptor sites specific to the molecules being internalized.