| A | B |
|---|
| acid | compound that is a proton donor |
| amino acid | organic molecule that is the building block of protein |
| atom | smallest unit of matter that cannot be broken down by chemical means |
| base | compound that is a proton acceptor |
| carbohydrate | organic compound composed of carbon, hydrogen, and oxygen; used by living things as an energy source |
| cell membrane | bilipid layer that encloses the cytoplasm, essential to the cell's cytoplasm; also called the plasma membrane |
| cell theory | principle that states all organisms are made of one or more cells that are derived from other cells |
| cellulose | carbohydrate that is the main structural component of cell walls |
| central vacuole | membrane-bound cavity in plant cells used for storage |
| centriole | rod-shaped organelle that help move chromosomes during cell division |
| chromosome | cellular structure on which genes are located |
| cilia | in cells, tightly packed rows of short flagella used for movement |
| collagen | fibrous structural protein present in all multicellular organisms, particularly in connective tissue |
| compound | substance that is made up of more than one kind of atom |
| cytoplasm | the material between the cell membrane and the nuclear membrane |
| cytoskeleton | cytoplasmic network of protein filaments that plays an essential role in cell movement, shape, and division |
| DNA (deoxyribonucleic acid) | nucleic acid that stores hereditary information |
| electron | elementary particle with negative electric charge |
| element | substance composed of a single type of atom |
| endoplasmic reticulum (ER) | cell membranes in the cytoplasm that transport substances made by the cell |
| enzyme | protein that catalyzes a chemical reaction |
| eukaryotic | complex cell that has nucleus enclosed by a membrane |
| evolution | change in the genetic makeup of a population or species over time |
| flagella | whiplike structures that grow out of a cell and enable it to move |
| glycogen | polymer of glucose used for short-term energy storage |
| Golgi apparatus | cell organelle of a eukaryotic cell that consists of flattened sacs and collects, packages, and distributes molecules produced by the cell |
| hydrogen bond | weak chemical bond in which a slightly positive hydrogen atom in a polar bond of one molecule is attracted to a slightly negative atom (usually oxygen or nitrogen) in a polar bond of another molecule |
| ion | electrically charged atom or molecule |
| ionic bond | chemical bond joining positive and negative ions |
| light microscope | microscope that uses a beam of light passing through one or more lenses |
| lysosome | cell organelle of a eukaryotic cell containing hydrolytic, digestive enzymes |
| magnification | enlargement or enlarging of an image |
| microtubule | hollow protein fiber in the cytoplasm of a eukaryotic cell involved in cell movement and structure |
| mitrochondrion | cell organelle of a eukaryotic cell that supplies the cell with ATP by performing oxidative respiration |
| molecule | smallest particle of a substance that retains all the properties of the substance and is composed of two or more atoms |
| nuclear envelope | double membrane that surrounds the cell nucleus |
| nucleic acid | organic molecule that stores information for cell function; DNA or RNA |
| nucleotide | subunit of nucleic acids consisting of a nitrogenous base, a sugar and a phosphate group |
| nucleus | the organelle that houses the DNA of eukaryotic cells |
| organelle | subcellular structure that has a special function |
| peroxisome | intracellular, membrane-bound organelle that contains oxidative enzymes and carries out oxidative reactions |
| pH scale | method of relating the hydrogen concentration in a solution |
| plasma membrane | thin layer on the surface of all cells, consisting mainly of lipids ands proteins |
| polar molecule | a molecule, such as water, that has positively and negatively charged ends |
| polypeptide | a chain of amino acids |
| polysaccharide | complex carbohydrate composed of three or more monosaccharides |
| prokaryotic | a cell without a nucleus |
| protein | organic compound formed of one or more chains of polypeptides |
| resolution | in microscopes, the ability to distinguish small, close objects |
| ribosome | cytoplasmic organelle on which proteins are synthesized |
| RNA (ribonucleic acid) | a type of nucleic acid that participates in the expression of genes |
| saturated fat | fat that contains no C=C bonds |
| scanning electron microscope (SEM) | microscope that scans the surface of an obkect with a beam of electrons, enabling the viewer to see three-dimensional images |
| starch | a storage form of glucose consisting of hundreds of glucose molecules |
| steriod | a class of lipids that includes cholesterol and some hormones |
| transmission electron microscope (TEM) | microscope that produces a stream of electrons that passes through a specimen and strikes a fluorescent screen |
| unsaturated fat | fat that contains C=C bonds |
| vesicle | membrane-enclosed sac in a cell's interior |
