Term | Definition |
Cell | Form the parts of an organism and carry out all of its functions. |
Microscope | An instrument that makes small objects look larger. |
Cell Theory | Is a widely accepted explanation of the relationship between cells and living things. |
Cell Wall | Surrounds the cells of plants and some other organisms. |
Cell Membrane | Controls which substance pass into and out of a cell. |
Nucleus | Acts as a cell's control center, directing all of the cell's activities. |
Organelles | Carry out specific functions within a cell. |
Ribosomes | Small grain-shaped organelles that produce proteins |
Cytoplasm | Fills the region between the cell membrane and the nucleus. |
Mitochondria | Convert energy stored in food to energy the cell can use to live and function. |
Endoplasmic Reticulum | Has a network of membranes that produce many substances |
Golgi Apparatus | Receives proteins and other newly formed materials in the ER, packages them, and distributes them to other parts of the cell or to the outside the cell. |
Vacuole | Stores water, food, or other materials needed by the cell. |
Chloroplast | Captures energy from sunlight and changes it to a form of energy cells can use in making food. |
Lysosomes | Contain substances that break down large food particles into smaller ones. |
Multicellular | Made of many cells. |
Unicellular | Single-celled organisms. |
Tissue | A group of similar cells that work together to perform a specific function. |
Organ | Made of different kinds of tissue that function together. |
Organ system | A group of organs that work together to perform a major function. |
Elements | Any substance that cannot be broken down into simpler substances. |
Compounds | When two or more elements combine chemically. (Carbon dioxide and water.) |
Carbohydrates | Energy-rich organic compounds made of the elements carbon, hydrogen, and oxygen. |
Lipids | Compounds that are made mostly of carbon and hydrogen and some oxygen. |
Proteins | Large organic molecules made of carbon, hydrogen, oxygen, nitrogen, and, in some cases, sulfur. |
Enzymes | Speed up chemical reactions in living things. |
Nucleic Acids | Very long organic molecules. |
DNA | Genetic material that carries information about an organism and is passed from parent to offspring. |
Double Helix | The shape of a DNA molecule. |
Selectively Permeable | Some substances can cross the membrane while others cannot. |
Passive Transport | The movement of dissolved materials across a cell membrane without using the cell's energy. |
Diffusion | The process by which molecules move from an area of higher concentration to an area of lower concentration. |
Osmosis | The diffusion of water molecules across a selectively permeable membrane. |
Active Transport | The movement of materials across a cell membrane using cellular energy. |
Endocytosis | The cell membrane changes shape and engulfs the particle. |
Exocytosis | Allows large particles to leave a cell. |