| Question |
Answer |
| cell theory |
the theory that states that all living things are made up of cells, that cells are basic units of organisms, that each cell in a multicellular organism has a specific job, and that cells come from only existing cells |
| cytoplasm |
the region of cell within the membrane that includes the fluid, the cytoskeleton, and all of the organelles except the nucleus |
| organelle |
one of the small bodies that are specialized to perform a specific function |
| 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 |
the cytoplasm network of protein filaments that plays as essential role in cell movement, shape, division |
| nucleus |
in a eukaryotic cell, a membrane-bound organelle that contains the cells 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 |
the cell organelle composed of RNA and protein; the site of protein synthesis |
| Golgi apparatus |
a call 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 |
in eukaryotic cells, the cell organelle that is surrounded by two membranes and that is the site of cellular respiration, which produces ATP |
| 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 up of protein tubes arranged in color; aids mitosis |
| cell wall |
rigid structure that gives protection, support, and shape to cells in plants, algae, fungi, and bacteria |
| chloroplast |
an organelle found in plant and algae cells where photosynthesis occurs |
| 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 |
a lipid that contains phosphorus and that is a structural component in cell membranes |
| 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 barrier or membrane |
| receptor |
protein that detects a signal molecule and performs an action in response |
| passive transport |
the movement of substances across the 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 concentration of a substance across a distance |
| osmosis |
the diffusion of water or another solvent from a more dilute solution (of a solute) to a more concentrated solution (of the solute) through the membrane that is permeable to the solvent |
| isotonic |
solution that has an equal concentration of dissolved particles compared with another solution |
| 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 my which the cell membrane surrounds a particle and encloses the particle in a vesicle to bring the particle into the cell |
| phagocytosis |
uptake of a solid particle into a cell by engulfing the particle |
| exocytosis |
the process by which a substance is released from a cell through a vesicle that transports the substance to cell surface and then fuses with the membrane to let the substance out |
