Hyperthermophilic environments: Hydrothermal vents from: NOAA from: NOAA www.naturalhistorymag.com

Three stages of metabolism

Glycolysis •2 ATPs per glucose used •4 ATPs and 2 NADHs generated per glucose NET: 2 ATPs, 2 NADHs Many of the 3C compounds can be used in the synthesis of cell components.

TCA Cycle •Pyruvate (3C) from gycolysis gets converted to AcetylCoA (2C) and a NADH which is added to Oxalacetic acid (4C) to give citrate (6C). •The acetylCoA part of gets citrate gets oxidized to CO2, giving Oxalacetic acid, 3 NADHs, 1 FADH2 and a GTP (converted to ATP) •This happens twice (each glucose gets converted to 2 pyruvates in glycolysis). •a-ketoglutarate is a very important intermediate used in biosynthesis

Pentose Phosphate Cycle •Glucose is also broken down by the PPC to make NADPH and biosynthetic intermediates •Takes 3 glucose (18C) and converts them to: 2 fructose (12C) + 1 Glyceraldehyde-3-P (3C) 3 CO2 (3C) •Generates 3 NADPHs in the process. These are used for reducing reactions in biosynth. •Many of the intermediates 5C, 3C, 7C are used in the biosynthesis of cell material (see green dots on map)------->

Fermentation pathways

Mitochondrial Electron Transport Chains Very similar to standard bacterial aerobic respiration chains

Relationship of electron donors and acceptors

Mitochondrial Electron Transport Chains Very similar to standard bacterial aerobic respiration chains

Eo’ of electron donors and acceptors in the mitochondrial electron transport chain

ATP synthesis by electron transport chains

Iron precipitation at near an iron mine: Iron rich (Fe2+) anaerobic waters become oxygenated at the surface