Chapter 19 extras: Prokaryotes: The First Single-Celled Creatures

Supplementary videos

HIV life cycle: reverse transcriptase, integrase, protease (44 MB) (HHMI)
HIV treatment: AZT blocks reverse transcriptase (HHMI)
HIV treatment: Ritonavir protease inhibitor (HHMI)
Endogenous retroviruses: life cycle and ancestral implications

Extra credit readings