| A | B |
|---|
| cell | the basic unit of structure and function in living things |
| microscope | an instrument that makes small objects look larger |
| cell theory | an explanation of the relationship between cells and living things |
| organelle | a tiny cell structure that carries out a specific function within the cell |
| cell wall | a rigid layer of nonliving material that surrounds the cells of plants and some organisms |
| cell membrane | a cell structure that controls which substances can enter or leave the cell |
| nucleus | a cell structure that contains the nucleic acids, the chemical instructions that directs all the cell activities |
| cytoplasm | the region between the cell membrane and the nucleus |
| mitochondria | rod or pill shaped cell structures that convert energy in food molecules to energy the cell can use to carry out is functions |
| endoplasmic reticulum | a cell structure that forms a maze of passageways in which proteins and other materials are carried from one part of the cell to another part |
| ribosome | a small grain like structure in the cytoplasm of a cell where proteins are made |
| Golgi body | a cell structure that receives proteins and other newly formed materials from the E.R., packages them and distributes to other parts of the cell |
| chloroplast | a structure in plant cells that captures energy from the sunlight and uses it to produce food |
| vacuole | a sac inside a cell that acts as a storage area |
| lysosome | a small round cell structure containing chemicals that break down large food particles into smaller ones |
| element | any substance that cannot be broken down into simpler substances |
| compound | two or more elements that are chemically combined |
| carbohydrate | energy rich organic compound such as sugar or starch that is made of the elements of carbon, hydrogen and oxygen |
| protein | large organic molecule made of carbon, hydrogen, oxygen, nitrogen and sometimes sulfur |
| amino acid | a small molecule that is linked chemically to others to form proteins |
| enzyme | a type of protein that speeds up a chemical reaction in a living thing |
| lipid | energy rich organic compound such as a fat, oil, or wax, that is made of hydrogen, carbon and oxygen |
| nucleic acid | very large organic molecule that contains the instructions cells need to carry out all the functions of life |
| DNA | Deoxyribonucelic 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 move from an area of higher concentration to an area of lower concentration |
| osmosis | the diffusion of water molecules through a selectively permeable membrane |
| passive transport | the movement of materials through a cell membrane without using energy |
| active transport | the movement of materials through a membrane using energy |
