Chapter 3 of 10All chapters
Chapter 3 of 10
DNA
A four letter instruction set.
Structure
Two strands twist around each other, held by paired bases: A with T, C with G. Because the pairing is fixed, each strand carries the information to rebuild the other, which is how copying works.
- The human genome is about three billion base pairs.
- Only a small fraction directly codes for proteins.
From gene to protein
A gene is transcribed into RNA and translated into a chain of amino acids that folds into a protein. Proteins then do nearly all the work of the cell.