| A | B |
|---|
| Absorption | The transport of dissolved substances into cells |
| Activation energy | Energy necessary to get a chemical reaction going |
| Active transport | Movement of molecules through the plasma membrane (typically opposite the dictates of osmosis or diffusion) aided by a chemical process |
| Anticondon | A three-nucleoctide sequence on tRNA |
| Cell wall | A rigid substance on the outside of certain cells, usually plant and bacteria cells |
| Central vacuole | A large vacuole that rests at the center of most plant cells and is filled with a solution which contains a high concentration of solutes |
| Chromatin | Clusters of DNA and proteins in the nucleus |
| Chromoplasts | Organelles that contain pigments used in photosynthesis |
| Codon | A sequence of three nucleotides on mRNA that refer to a specific type of amino acid |
| Cytology | The study of cells |
| Cytolysis | The rupturing of a cell due to excess internal pressure |
| Cytoplasm | A jelly-like fluid inside the cell in which the organelles are suspended |
| Cytoplasmic streaming | The motion of the cytoplasm which results in a coordinated movement of the cell's organelles |
| Digestion | The breakdown of absorbed substances |
| Egestion | The removal of non-soluble waste materials |
| Endoplasmic reticulum | An organelle composed of an extensive network of folded membranes which perform several tasks within a cell |
| Excretion | The removal of soluble waste materials |
| Golgi bodies | The organelles where proteins and lipids are stored and then modified to suit the needs of the cell |
| Homeostasis | Maintaining the status quo in a cell |
| Hypertonic solution | A solution in which the concentration of solutes is greater than that of the cell which resides in the solution |
| Ions | Substances in which at least one atom has an imbalance of protons and electrons |
| Isotonic solution | A solution in which the concentration of solutes is essentially equal to that of the cell which resides in the solution |
| Leucoplasts | Organelles that store starches or oils |
| Lysosome | The organelle in animal cells responsible for hydrolysis reactions which break down proteins, polysaccharides, disaccharides, and some lipids |
| Messenger RNA | The RNA that performs transcription |
| Microtubules | Spiral strands of protein molecules that form a rope-like structure |
| Middle lamella | The thin film between the cell walls of adjacent plant cells |
| Mitochondria | The organelles in which nutrients are converted to energy |
| Nuclear membrane | A highly-porous membrane that separates the nucleus from the cytoplasm |
| Passive transport | Movement of molecules through the plasma membrane according to the dictates of osmosis or diffusion |
| Phagocytic vacuole | A vacuole that holds the matter which a cell engulfs |
| Phagocytosis | The process by which a cell engulfs foreign substances or other cells |
| Phospholipid | A lipid in which one of the fatty acid molecules has been replaced by a molecule which contains a phosphate group |
| Pinocytic vesicle | Vesicle formed at the plasma membrane to allow the absorption of large molecules |
| Plasma membrane | The semipermeable membrane between the cell contents and either the cell wall or the cell's surroundings |
| Plasmolysis | A collapse of the cell's cytoplasm due to lack of water |
| Reproduction | Producing more cells |
| Respiration | The breakdown of food molecules with a release of energy |
| Ribosomes | Non-membrane-bound organelles responsible for protein synthesis |
| Rough endoplasmic reticulum | ER that is dotted with ribosomes |
| Secretion | The release of biosynthesized substances for use by other cells |
| Secretion vesicle | Vesicle that holds secretion products so that they can be transported to the plasma membrane and released |
| Smooth endoplasmic reticulum | ER that has no ribosomes |
| Transcription | The process in which mRNA produces a negative of a strand of DNA |
| Translation | The process by which proteins are formed in the ribosome according to the negative in mRNA |
| Waste vacuoles | Vacuoles that contain the waste products of digestion |
