click below
click below
Normal Size Small Size show me how
cells
biology
Term | Definition |
---|---|
CELL THEORY | a theory in biology that cells are the basic units of structure and function in living organisms. |
CYTOPLASM | the material or protoplasm within a living cell, excluding the nucleus. |
ORGENELL | any of a number of organized or specialized structures within a living cell. |
PROKARYOTIC CELL | are unicellular organisms that lack organelles or other internal membrane-bound structures . Therefore, they do not have a nucleus, but, instead, generally have a single chromosome |
EUKARYOTIC CELL | A eukaryote is any organism whose cells contain a nucleus and other organelles enclosed within membranes |
CYTOSKELETON | the cytoplasmic network of protein filaments that plays an essential role in cell movement, shape, and division |
NUCLEUS | in physical science, an atom's central region, which is made up of protons and neutrons |
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 | |
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 | 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 | |
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 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 | |
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 | |
EXOCYTOSIS |