| A | B |
|---|
| element | A type of matter on which all the atoms are the same; cannot be broken down into simpler substances. |
| atom | The smallest unit of an element. |
| compound | Two or more elements that are chemically combined. |
| molecule | The smallest unit of most compounds. |
| organic compound | A compound that contains carbon. |
| inorganic compound | A compound that does not contain carbon. |
| protein | Large organic molecules made of carbon, hydrogen, oxygen, nitrogen, and sometimes sulfur; they are needed for tissue growth and repair and play a part in chemical reactions within cells. |
| amino acid | Small units that are linked together chemically to form large protein molecules. |
| enzyme | A protein that speeds up chemical reactions in the bodies of living things. |
| carbohydrates | Energy-rich organic compounds, such as sugars and starches, that are made up of the elements carbon, hydrogen, and oxygen. They provide the raw materials to make parts of cells. |
| lipids | Energy-rich organic compounds, such as fats, oils, and waxes, that are made of carbon, hydrogen, and oxygen. |
| nucleic acid | A very large organic molecule made of carbon, oxygen, hydrogen, nitrogen and phospherous, that contains instructions that cells need to carry out all the functions of life. |
| DNA | Deoxyribonucleic acid; the genetic material that carries information about an organism and is passed from parent to offspring. |
| RNA | Ribonucleic acid; a nucleic acid that plays an important role in the production of proteins. |
| selectively permeable | A property of cell membranes that allows some substances to pass through, while others cannot. |
| diffusion | The process by which molecules mive from an area in which they are highly concentrated to an area in which thay are less concentrated. |
| osmosis | The diffusion of water molecules through a selectively permeable membrane. |
| passive transport | The movement of materials through a cell membrane without the use of energy. |
| active transport | The movement of materials through a cell membrane using energy. |
| photosythesis | The process by which plants and some other organisms capture light energy and use it to make food from carbon dioxide and water. |
| pigment | A colored chemical compound that absorbs light, producing color. |
| chlorophyll | A green pigmentfound in the chloroplasts of plants, algae, and some bacteria. |
| stomata | The small openings on the undersides of most leaves through which oxygen and carbon dioxide can move. |
| respiration | The process by which cells break down simple food molecules to release the energy they contain. |
| fermentation | The process by which cells break down molecules to release enrgy without using oxygen. |
| cell cycle | The regular sequence of growth and division that cells undergo. |
| interphase | The stage of the cell cycle that takes place before the cell division occurs; during this stage, the cell grows, copies its DNA, and prepares to divide. |
| replication | The process by which the cell makes a copy of the DNA in its nucleus. |
| mitosis | The stage of the cell cycle during which the cell's nucleus divides into two new nuclei and one copy of the DNA is distributed into each daughter cell. |
| chromosome | A rod-shaped cellular structure made of condensed chromatin; contains DNA, which carries the genetic information that controls inherited characteristics such as eye color and blood type. |
| chromatid | One of the identical rods of a chromosome. |
| cytokinesis | The final stage of the cell cycle, in which the cell's cytoplasm divides, distributing the organelles into each of the two new cells. |
