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Chapter 9: DNA
DNA- The Genetic Material
| Term | Definition |
|---|---|
| Double helix | the shape of the DNA molecule (Watson and Crick) |
| Nucleotide | a piece of the DNA molecule, made of a phosphate, a sugar and a base |
| Base- pairing rules | A pairs with T (2 bonds) and G pairs with C (3 bonds) |
| Complementary base pair | the sequence of bases on one strand, or side, determines the sequence of the bases on the other strand, or side |
| Purines | 2, or double, ring bases (A and G) |
| Pyrimidines | 1, or single, ring bases (T and C) |
| Adenine (A) | always pairs with T, 2 bonds |
| Thymine (T) | always pairs with A, 2 bonds |
| Cytosine (C) | always pairs with G, 3 bonds |
| Guanine (G) | always pairs with C, 3 bonds |
| DNA replication | making a copy of DNA so the cell can reproduce, during Synthesis phase |
| DNA helicase | the chemical that opens the double helix by breaking the bonds between the bases on the opposite strands |
| replication fork | the areas where the double helix separates |
| DNA polymerase | the chemical that moves along the DNA strands and adds nucleotides according to the base-pairing rules |