| A | B |
|---|
| acid | any substance that forms hydrogen ions in water |
| amino acid | basic building blocks of protein molecules |
| base | substance that forms hydroxide ions in water |
| carbohydrate | organic compound used by cells to store and release energy |
| cellulose | polysaccharide made of glucose used to make plant cell walls |
| compound | any substance composed of atoms of different elements |
| covalent bond | chemical bond formed by sharing of electrons |
| disaccharide | a two-sugar carbohydrate |
| DNA | a nucleic acid which passes on genetic information each time a cell divides |
| enzyme | a protein that accelerates chemical reactions but remains unchanged itself |
| glycogen | polysaccharide with highly branched chains of glucose used by animals to store food |
| hydrogen bond | weak bond between hydrogen and other atoms |
| ion | atom or molecule with a positive or negative charge |
| ionic bond | bond formed by attraction between ions of opposite charges |
| isomer | compounds with same formula but different arrangements of their atoms |
| isotope | atoms of the same element with different numbers of neutrons |
| lipid | organic compounds commonly called fats and oils |
| metabolism | total of all chemical reactions that occur within a living organism |
| molecule | group of atoms held together by covalent bonds |
| monosaccharide | a simple sugar such as glucose |
| nucleic acid | complex macromolecule like DNA which stores information in the cells |
| nucleotide | subunits of nucleic acids formed from a simple sugar, a nitrogen base, and a phosphate |
| nucleus | positively charged center of an atom |
| peptide bond | covalent bond linking amino acids |
| pH | symbol used to describe strength of acids and bases |
| polar molecule | molecule with a positive and negative end |
| polysaccharide | largest carbohydrate molecules; composed of monosaccharide subunits |
| protein | polymer made of amino acids; important in muscle contraction and providing immunity |
| RNA | ribonucleic acid; it forms copies of DNA |
| starch | polysaccharide used to store food in plants |
