Term | Definition |
Cell Theory | The scientific theory describing cells and that all cells are produced only from pre-existing, living cells |
Cytoplasm | Consists of all of the contents outside of the nucleus and enclosed within the cell membrane of a cell. |
Organelle | Compartment or structure in a cell that performs a special function. |
Prokaryotic Cell | An organism whose cell generally lacks a true nucleus |
Eukaryotic Cell | An organism that possesses a membrane-bound nucleus |
Cytoskeleton | The cytoplasmic network of protein filaments that plays an essential role in cell movement, shape, and division |
Nucleus | The cell’s DNA and that has a role in processes such as growth, metabolism, and reproduction |
Endoplasmic Reticulum | A system of membranes that is found in a cell's cytoplasm and that assists in the production, processing, and transport of proteins and in the production of lipids |
Ribosome | A cell organelle composed of RNA and protein; the site of protein synthesis |
Golgi Apparatus | A cell organelle that helps make and package materials to be transported out of the cell |
Vesicle | A small cavity or sac that contains materials in a eukaryotic cell; forms when part of the cell membrane surrounds the materials to be taken into the cell or transported within the cell |
Mitochondrion | |
Vacuole | A fluid-filled vesicle found in the cytoplasm of plant cells or protozoans |
Lysosome | A cell organelle that contains digestive enzymes |
Centriole | An organelle that is active during mitosis |
Cell Wall | A rigid structure that surrounds the cell membrane and provides support to the cell |
Chloroplast | An organelle found in plant and algae cells where photosynthesis occurs |
Cell Membrane | A phospholipid layer that covers a cell’s surface and acts as a barrier between the inside of a cell and the cell’s environment |
Phospholipid | A lipid that contains phosphorus and that is a structural component in cell membranes |
Fluid Mosaic Model | |
Selective Permeability | |
Receptor | A specialized sensory nerve that responds to specific types of stimuli |
Passive Transport | The movement of substances across a cell membrane without the use of energy by the cell |
Diffusion | The movement of particles from regions of higher density to regions of lower density |
Concentration Gradient | A difference in the concentration of a substance across a distance |
Osmosis | The diffusion of water or another solvent from a more dilute solution to a more concentrated solution through a membrane that is permeable to the solvent |
Isotonic | |
Hypertonic | Describes a solution whose solute concentration is higher than the solute concentration inside a cell |
Hypotonic | Describes a solution whose solute concentration is lower than the solute concentration inside a cell |
Facilitated Diffusion | The transport of substances through a cell membrane along a concentration gradient with the aid of carrier proteins |
Active Transport | The movement of chemical substances, usually across the cell membrane, against a concentration gradient; requires cells to use energy |
Endocytosis | The process by which a cell membrane surrounds a particle and encloses the particle in a vesicle to bring the particle into the cell |
Phagocytosis | The process by which a cell engulfs large particles or whole cells, either as a defense mechanism or as a means to obtain food |
Exocytosis | The process by which a substance is released from the cell through a vesicle that transports the substance to the cell surface and then fuses with the membrane to let the substance out |