Term | Definition |
Cell Theory | Theory that states that all organisms are made of cells, all cells produced by other livings cells, and the cell is the most basic unit of life. |
Cytoplasm | Jellylike substance inside cells that contains molecules and in some cells organelles |
Organelle | Membrane-bound structure that is specialized to perform a distinct process within a cell. |
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. |
Cytoskeleton | Network of proteins, such as microtubules and microfilaments, inside a eukaryotic cell that supports and shapes the cell. |
Nucleus | Organelle composed of double membrane that acts as the storehouse for most of a cell's DNA. |
Endoplasmic Reticulum | Interconnected network of thin, folded membranes that produce, process, and distribute proteins. |
Ribosome | Organelle that links amino acids together to form proteins.. |
Golgi Apparatus | Stack of flat, membrane-enclosed spaces containing enzymes that process, sort, and deliver proteins. |
Vesicle | Small organelle that contains and transports materials within the cytoplasm. |
Mitochondrion | Bean-shaped organelle that supplies energy to the cell and has its own ribosomes and DNA. |
Vacuole | Organelle that is used to store materials, such as water, food, or enzymes, that are needed by the cells. |
Lysosome | Organelle that contains enzymes. |
Centriole | Small cylinder-shaped organelle made of protein tubes arranged in a circle; aids mitosis. |
Cell Wall | Rigid structure that gives protection, support, and shape to cells in plants, algae, fungi, and bacteria. |
Chloroplast | Organelle composed of numerous membranes that are used to convert solar energy into chemical energy; contains chlorophyll |
Cell membrane | Double-layer of phospholipids that forms a boundary between a cell and the surrounding environment and controls the passage of materials into and out of a cell. |
Phospholipid | Molecule that forms a double-layered cell membrane; consists of glycerol, a phosphate group, and two fatty acids. |
Fluid Mosaic Model | Model that describes the arrangement and movement of the molecules that make up a cell membrane. |
Selective Permeability | Condition or quality of allowing some, but not all, materials to cross a barrier or membrane. |
Receptor | Protein that detects a signal molecule and performs and action in response. |
Passive Transport | Movement of molecules across the cell membrane without energy input from the cell. |
Diffusion | Movement of dissolved molecules in a fluid or gas from a region of higher concentration to a region of lower concentration. |
Concentration Gradient | Difference in the concentration of a substance from one location to another. |
Osmosis | Diffusion of water molecules across a semipermeable membrane from an area of higher water concentration to an area of lower water concentration. |
Isotonic | Solution that has an equal concentration of dissolved particles compared with another solution. |
Hypertonic | Solution that has higher concentration of dissolved particles compared with another solutions. |
Hypotonic | Solution that has a lower concentration of dissolved particles compared with another solution. |
Facilitated Diffusion | Diffusion of molecules assisted by protein channels that pierce a cell membrane. |
Active Transport | Energy-requiring movement of molecules across a membrane from a region of lower concentration to a region of higher concentration |
Endocytosis | Uptake of liquids or large molecules into a cell by inward folding of cell membrane. |
Phagocytosis | Uptake of a solid particle into a cell y engulfing the particle; see endocytosis. |
Exocytosis | Release if substance out of a cell by the fusion of a vesicle with the membrane. |