| A | B |
|---|
| active transport | the movement of particles from an area of low concentration to an area of high concentration that uses energy provided by ATP or a difference in electrical charges across a cell membrane |
| Adenosine triphosphate (ATP) | a molecule that provides energy for cellular reactions and processes. ATP releases energy when one of its high-energy bonds is broken to release a phosphate group |
| carrier (transport) proteins | proteins embedded in the plasma membrane involved in the movement of ions, small molecules, and macromolecules into and out of cells; also known as transport proteins |
| concentration | the measure of the amount or proportion of a given substance when combined with another substance |
| concentration gradient | the graduated difference in concentration of a solute per unit distance through a solution |
| diffusion | the movement of particles from an area of high concentration to an area of low concentration; a natural result of kinetic molecule energy |
| endocytosis | a process in which a cell engulfs extracellular material through an inward folding of its plasma membrane |
| endosymbiosis | a theorized process in which early eukaryotic cells were formed from simpler prokaryotes |
| exocytosis | a process in which a cell releases substances to the extracellular environment by fusing a vesicular membrane with the plasma membrane, separating the membrane at the point of fusion and allowing the substance to be released |
| extracellular | located outside a cell |
| facilitated diffusion | a process in which substances are transported across a plasma membrane with the concentration gradient with the aid of carrier (transport) proteins; does not require the use of energy |
| homeostasis | the regulatory process in which an organism regulates its internal environment |
| impermeable | not permitting passage of a substance or substances |
| intracellular | located inside a cell |
| lipids | a group of organic compounds composed mostly of carbon and hydrogen including a proportionately smaller amount of oxygen; are insoluble in water, serve as a source of stored energy, and are a component of cell membrane |
| osmosis | the movement of water or another solvent through permeable membranes from an area of higher water concentration (dilute) to an area of lower water concentration (concentrated) |
| passive transport | the transportation of materials across a plasma membrane without using energy |
| protein | a macromolecule that contains the principal components of organisms: carbon, hydrogen, oxygen, and nitrogen; performs a variety of structural and regulatory functions for cells |
| pumps (ion or molecule) | any of several molecular mechanisms in which ions or moleculare are transported across a cellular membrane requiring the use of an energy source ( eg. glucose, sodium (NA+), calcium (Ca+) and potassium (K+) |
