| A | B |
|---|
| carbohydrates | group of chemicals that include sugar, starches, and cellulose |
| lipids | group of chemicals that include fats, oils, waxes, phospholipids and steroids |
| proteins | large complex molecules of many smaller molecules called amino acids |
| nucleic acids | large complex molecules that contain hereditary, or genetic, information |
| elements | a substance that cannot be broken down by chemical process into simpler substances |
| compound | a substance made of two or more elements chemically combined in definite proportions |
| organic compound | generally associated with living things |
| ion | an atom that has lost or gained electrons |
| isotopes | atoms of the same elements that have different number of neutrons |
| chemical bonds | attraction that holds two or more atoms together to form a compound |
| chemical reactions | one or more substance is changed into a new substance by breaking or forming of chemical bond |
| enzyme | a protein catalyst that speeds up the chemical reaction within an organism |
| metabolism | the combination of all the chemical changes that take place in an organism |
| homeostasis | the tendency of an organism to maintain stable internal conditions |
| solution | a uniform mixture of two or more substances |
| acid | a compound that releases hydrogen H+ ions in water |
| base | a compound that produces hydroxide ions (OH-) when dissolved in water |
| pH scale | standard measurement or concentration of hydrogen ions present in a solution (from 0-14) |
| catalyst | compound that changes reaction rate |
| isomer | same chemical formula but different structure |
