| A | B |
|---|
| cell | the basic unit of structure and function in living things |
| cell theory | a widely accepted explanation of the relationship between cells and living things |
| cell membrane | a thin, flexible barrier that surrounds a cell and controls which substances pass into and out of a cell |
| cell wall | a rigis supporting layer that surrounds the cells of plants and some other organisms |
| cytoplasm | the thick fluid region of a cell located inside the cell membrane or between the cell membrane and nucleus |
| chloroplast | an organelle in the cells of plants and some other organisms that captures energy from sunlight and changes it to an energy form that a cells can use in making food |
| carbohydrate | an energy-rich organic compund, such as a sugar or a starch, that is made of the elements carbon, hydrogen, and oxygen |
| compound | a substance made of two or more elements and chemically combined in a specific ratio or proportion |
| endoplasmic reticulum | an organelle that forms a maze of passageways in which proteins and other materials are carried from one part of the cell to another |
| element | a pure substance that cannot be broken down into other substances by chemical or physical means |
| DNA | the genetic material that carries information about an organism and is passed from parent to offspring |
| double helix | the shape of a DNA molecule |
| endocytosis | the process by which the cell memebrane takes particles into the cell by changing shape and engulfing the particles |
| exocytosis | the process by which the vacuole surrounding particles fuses with the cell membrane, forcing the contents out of the cell |
| Golgi apparatus | an organelle in a cell that receives proteins and other newly formed materials from the endoplasmic reticulum, packages them, and distributes them to other parts of the cell |
| enzyme | a type of protein that speeds up a chemical reaction in a living thing |
| microscope | an instrument that makes small objects look larger |
| nucleus | in cells, a large oval organelle that contains the cell's genetic material in the form of DNA and controls many of the cell's activities |
| mitochondria | rod shaped organelles that convert energy in food molecules to energy the cell can use to carry out its functions |
| lysosome | a cell organelle whic contains chemicals that break down large food particles into smaller ones and that acan be used by the rest of the cell |
| multicellular | consisting of many cells |
| lipid | an energy rich organic compound , such as a fat, oil, or wax, that is made of carbon, hydrogen , and oxygen |
| nucleic acid | a very large organic molecule made of carbon, oxygen, hydrogen, nitrogen, and phosphorus , that contains the instructions cells need to carry out all the functions of life |
| diffusion | the process by which molecules move from an area of higher concentration to an area of lower concentration |
| organelle | a tiny cell structure that carries out a specific function within the cell |
| osmosis | the diffusion of water molecules across a selectively permeable membrane |
| ribosome | a small grain-shaped organelle in the cytoplasm of a cell that produces proteins |
| organ | a body structure that is composed of different kinds of tissues that work together |
| organ system | a group of organs that work together to perform a major function |
| protein | large organic molecule made of carbon, hydrogen, oxygen, notirogen, and sometimes sulfur |
| passive transport | the movement of dissolved materials across a cell memebrane without using cellular energy |
| active transport | the movement of materials across cell membrane using cellular energy |
| vacuole | a sac-like organelle that sotres, water, food, and other materials |
| unicellular | made up of a single cell |
| tissue | a group of similar cells that perform a specific function |
| selectively permeable | a property of cell membranes that allows some substances to pass across it, while others cannot |
