| A | B |
|---|
| deoxyribose | the six carbon sugar found in DNA |
| phosphate group | in phosphorus atoms surrounded by oxygen atoms |
| nitrogen containing base | a nitrogen molecule found in DNA. |
| adenine | a nitrogen containing base, abbreviated A, that pairs with thymine |
| guanine | a nitrogen containing base, abbreviated G, that pairs with cytosine |
| cytosine | a nitrogen base, abbreviated C, that pairs with guanine |
| thymine | a nitrogen base, abbreviated T, that pairs with editing |
| purines | bases that have two rings of carbon and nitrogen atoms, such as adenine, and guanine |
| pyrimidine | bases that have one ring of carbon and nitrogen atoms, such as cytosine and thymine |
| double helix | the shape of DNA. |
| complementary base pairs | cytosine and guanine; adenine and thymine |
| replication | the process of DNA copying |
| replication fork | during DNA replication, the point where the two chains separate |
| helicase | the enzyme that breaks hydrogen bonds between the complementary bases and separates, or unzips DNA |
| DNA polymerase | enzymes that move along the separated chains of DNA and assemble a new chains of DNA using nucleotides in the surrounding medium |
| mutation | a change in the nucleotide sequence |
