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Biology Chapter 2
| Term | Definition |
|---|---|
| element | one particular type of atom, it cannot be broken down into a simpler substance by ordinary chemical means |
| atom | smallest basic unit of matter |
| compound | a substance made of atoms of different elements bonded together in a certain ratio |
| ion | an atom that has gained or lost one or more electrons |
| ionic bond | forms through the electrical force between oppositely charged ions |
| covalent bonds | forms when atoms share a pair of electrons |
| molecule | two or more atoms held together by covalent bonds |
| hydrogen bond | an attraction between a slightly positively charged hydrogen atom and a slightly negatively charged hydrogen atom |
| cohesion | the attraction among molecules of a substance |
| adhesion | the attraction among molecules of different substances |
| solution | a mixture of substances that is the same throughout- it is a homogenous mixture |
| solute | a substance that dissolves in a solvent |
| solvent | the substance that is present in the greater amount and that dissolves in another substance |
| monomer | each subunit in the complete molecule |
| polymer | a large molecule, or a macromolecule, made of many monomers bonded together |
| carbohydrates | molecules composed of carbon, hydrogen, and oxygen, and they include sugars and starches |
| lipids | nonpolar molecules that include fats, oils, and cholesterol |
| protein | a polymer made of monomers called amino acids |
| amino acids | molecules that contain carbon, hydrogen, oxygen, nitrogen, and sometimes sulfur |
| nucleic acid | polymers that are made up of the |