Term | Definition |
active transport | the process by which cells use energy to transport molecules through the cell membrane from areas of low concentration to areas of high concentration |
amino acids | any one of several building blocks of protein |
cell | the basic unit of structure and function that makes up all organisms |
cell membrane | the thin boundary between the cell and its environment |
cell respiration | the process in which nutrients are broken apart, releasing the chemical energy stored in them |
chloroplast | the green organelle that contains chlorophyll; where photosynthesis takes place |
circulation | the flow of materials within a cell as well as between parts of a multicellular organism |
cytoplasm | the jellylike substance that is between the cell membrane and the nucleus and that contains specialized structures |
diffusion | the movement of molecules from areas of high concentration to areas of low concentration |
digestion | the process that breaks down large food molecules into simpler molecules that the organism can use |
enzymes | proteins that speed up the rate of chemical reactions in living things |
excretion | the removal of all the wastes produced by the cells of the body |
homeostasis | the ability of an organism to maintain a stable internal environment even when the external environment changes |
hormone | a chemical produced in the endocrine glands |
immunity | the body's ability to destroy pathogens before they cause disease |
inorganic | a type of molecule that does not contain both carbon and hydrogen but can contain any other combination of elements |
metabolism | all the chemical reactions that occur within the cells of an organism |
mitochondria | pod-shaped organelles that contain enzymes used to extract energy from nutrients |
nucleus | a large structure within a cell that controls the cell's metabolism and stores genetic information, including chromosomes and DNA |
organ | a body structure made of different kinds of tissues combined to perform a specific function |
organ system | several organs that work together to perform a major function in the body |
organelle | a structure within the cell that carries out a specific function |
organic | term used to describe molecules that contain both hydrogen and carbon |
receptor molecule | certain protein molecules in the cell membrane that can receive chemical messages from other cells |
reproduction | the process by which organisms produce new organisms of the same type |
respiration | the process by which the chemical bond energy stored in nutrients is released for use in cells |
ribosome | one of the tiny structures in the cell that is the site of protein production |
simple sugars | the result of the digestion of starches. Example: glucose |
synthesis | a life process that involves combining simple substances into more complex substances |
tissue | a group of specialized cells that perform a specific function |
vacuole | storage sacs within the cytoplasm of a cell that may contain either wastes or useful materials, such as water or food |