DNA Structure
DNA Deoxyribonucleicacid is a complex molecule that carries genetic information. Its structure is crucial to understanding how it functions and replicates.
Definition: DNA is a double-stranded helix made up of repeating units called nucleotides.
A nucleotide consists of three components:
- Deoxyribose sugar
- Phosphate group
- Nitrogenous base
The sugar-phosphate backbone forms the outer part of the DNA strand, while the bases pair up in the center.
Vocabulary: Nucleotide - The basic structural unit of DNA, consisting of a sugar, phosphate, and base.
There are four types of nitrogenous bases in DNA:
- Adenine A
- Thymine T
- Cytosine C
- Guanine G
Highlight: Base pairing in DNA is specific: A pairs with T, and C pairs with G. This is known as complementary base pairing.
The two strands of DNA are antiparallel, meaning they run in opposite directions. One strand runs from 5' to 3', while the complementary strand runs from 3' to 5'.
Definition: Antiparallel strands - The two strands of DNA have their sugar-phosphate backbones running in opposite directions.