B1 Cells and Transport

Diffusion

Movement of molecules from an area of higher concentration to an area of lower concentration.

Osmosis

Diffusion of water through a selectively permeable membrane

Active transport

Energy-requiring process that moves material across a cell membrane against a concentration difference

Isotonic solution

A solution in which the concentration of solutes is essentially equal to that of the cell which resides in the solution

Hypertonic solution

Solute concentration is greater than that inside the cell; cell loses water

Hypotonic solution

Solute concentration is less than that inside the cell; cell gains water

Active transport requires

Energy and protein channels

Nucleus

A part of the cell containing DNA and controls the cells activities

Mitochondria

An organelle found in large numbers in most cells, in which respiration and energy production occur.

Ribosomes

Makes proteins

Cytoplasm

A jellylike fluid inside the cell in which reactions take place

Cell membrane

A cell structure that controls which substances can enter or leave the cell.

Chloroplast

An organelle found in plant and algae cells where photosynthesis occurs

Vacuole

Cell organelle in plants that stores cell sap

Magnification equation

Image size/actual size

Resolution

Ability of a microscope to distinguish two objects as separate

Prokaryotic cell

Cell that does not have a nucleus or other membrane-bound organelles.

Eukaryotic cell

Cell that has a nucleus and other membrane-bound organelles

Flaccid

A plant cell that is limp through a reduction of pressure inside the cell

Turgid

A plant cell fully inflated with water

Plasmolysed plant cell

The cell has lost water and the cytoplasm has shrunk; the membrane has pulled away from the cell wall

Crenated cell

An animal that has shrunk

Cell lysis

Swelling and bursting of animal cell