How Cells Work: The Basics
摘要
Deoxyribonucleic acid—DNA—is perhaps the most famous molecule in the world. If you close your eyes, you can probably picture its iconic double-helix shape, like a rope ladder twisted around its central axis. The “ropes” are long strings of simple sugars known as the sugar-phosphate backbone, connected by “rungs” made from much smaller organic molecules called nucleotides.