e- transferred from NADH and
FADH2 to
a final e- acceptor
• Results in a buildup of H+ ions
across membrane
1 NADH = 3 ATP
1 FADH2 =
2 ATP
In membrane (plasma or
mitochondrial)
O2 is
final acceptor in aerobic respiration ETC
Inorganic compound
other than O2 for
anaerobic respiration
Electron carriers are
reduced then oxidized to release energy
and hydrogen to outside
of membrane
Chemiosmosis says
diffusion from high to low concentration
across a membrane will
release energy (used for ATP)
Fig 5.15
Inner membrane = cytoplasmic
membrane
Outside = space between
membrane and cell wall
Inside = cytoplasm
1) NADH (FADH2)
oxidation
2) H+ pumped
across membrane
3)
Chemiosmotic generation of ATP
like water
behind a dam
Oxidase test in lab
Cytochrome C
E.coli and all Enterics are oxidase negative
pH 5 outside membrane
with H+ concentration
pH 8 in cytoplasm during H+
pumping
Fig. 5.17
•Oxygen as final electron acceptor
–Aerobic respiration
•Organic molecule (acid or alcohol) final
electron acceptor
–Fermentation
•Inorganic molecule but not oxygen
–Anaerobic respiration
Denitrifiers
NO3- -->
NO2-,
NO, N2O
or N2
Sulfate-Reducing Bacteria
SO42- -->
H2S
•ATP generation varies but lower than
aerobic respiration
•Only part of Krebs works without O2
•Only some of the carriers work in
ETC
•Both substrate and oxidative
phosphorylation
•Important for nutrient cycling –
–carbon, nitrogen, and sulfur
Biosynthesis (anabolism)
•ATP and intermediate compounds
are used
–Amphibolic Pathways
•Both catabolic and anabolic
•Sugar is used for energy
storage (glycogen) and cell walls (peptidoglycan)
•Lipids used for membranes
(phospholipids) and energy storage
•Amino acids/proteins enzymes
and structures
•Nucleic Acids for DNA and RNA
(next unit)
•