Prokaryotes (Bacteria and Archaea) are the most diverse organisms on Earth, possessing unique biochemical pathways and physiological adaptations that allow them to thrive in environments ranging from deep-sea vents to the human gut. Their physiology centers on how these single-celled organisms solve physical and chemical problems to grow, while their biochemistry explores the molecular mechanisms—such as enzyme function and metabolic flux—that sustain life. Key Physiological & Biochemical Themes
: All prokaryotes lack a nucleus but feature a nucleoid, ribosomes, and a plasma membrane; most possess a complex peptidoglycan cell wall. Physiology and Biochemistry of Prokaryotes
: Extremophiles utilize thermostable enzymes and unique cofactors like iron-sulfur clusters to function in high-heat or high-salinity conditions. Prokaryotes (Bacteria and Archaea) are the most diverse
Mechanisms for moving nutrients and proteins across membranes. Evolutionary relationships between Bacteria and Archaea. : Survival is driven by the proton motive
: Survival is driven by the proton motive force and membrane-bound electron transport chains that facilitate oxidative phosphorylation.
: Prokaryotes utilize diverse pathways, including the TCA cycle , glycolysis , and specialized fermentations or C1 metabolism .