Chapter 7 lecture notes
Definition of cellular respiration: catabolic pathway that harvests free energy from simple
carbohydrates> we will cover
Aerobic________________Anaerobic____________________
Fermentation___________________________
Redox Rxn: transfer of electron from one atom to another
Example: NaCL
Redox rxn of Cell resp: C6H12O6 + 6O2 6CO2 +6H2O+ energy (ATP)

Fuel is oxidized and oxygen is reduced. Energy of H is lowered as it is trasnfered from glucose to
h2o
 Activation energy prevents glucose from being consumed all at once.
 Cell Resp uses a series of redox rxns to strip electrons (H) 1 by 1 from glucose and add to
oxygen, releasing Energy
 NAD+ acts as an electron acceptor (oxidizing agent)
 NADH represents stored energy that is tapped to make ATP
 By transferring electron to ETC.
 Oxygen then pulls electron through ETC, pumping H+ out of mitochondria and creating
electrochemical gradient.H+ then falls back through ATP synthase
Glycolysis: rearragnges the bonds of glucose (6c) into 2 molecules of pyruvate (3C)
Key terms: Glucose, pyruvate, substrate level phosphorylation
 uses two ATP
 Creates: 2 Pyruvate, 4 ATP, 2 NADH
 Define: substrate-level phosphorylation: Direct transfer of Phos Group from org. molecule
 Location: outside mitochondria
Krebs Cycle: Pyruvate enters mitochondrial matrix and is further decomposed. Electrons collected and
taken to ETC
Key terms: NAD+/H
 Pyruvate is oxidized into Acetyl CoA
 6CO2 is released (remind of equation), 2 ATP produced (substrate level phosphorylation)
 8 NADH, 2 FADH created (carriers of electrons that were stripped off of pyruvate)
 Location: inside MM
ETC: Captures free energy from electrons carried by NADH and FADH in a series of coupled reactions
that establish an electrochemical gradient across membranes. What does this mean?
 Two parts: Electron transport chain and Chemiosmosis
 electrons fall through series of membrane proteins on their way to oxygen (terminal Electron
acceptor)
 proteins work to pump hydrogen protons (H+) into inner-membrane space of mito.
o Established a electrochemical gradient
 Protons then fall back into matrix, powering ATP Synthase
 Uses one O2
 Creates: 26-28 ATP through Oxidative phosphorylation
Fermentation and anaerobic respiration
Anaerobic has ETC, final electron acceptor is something other than oxygen
Used by prokaryotic organisms living in environments W/O oxygen
Type of cellular respiration
Fermentation No electron transport chain, an extension of glycolysis that transfers e- from NADH to
pyruvate
Harvesting energy (oxidization) without cellular respiration
Must have adequate supply of NAD+ must have a way to recycle NADH after it oxidizes
In cell resp this happens in ETC
Alcoholic fermentation pyruvate converted to ethanol (releases CO2)
Lactic Acid fermentation pyruvate converted to lactate (no CO2 released)
Much less efficient than aerobic respiration (only 2 ATP per cycle)
Cellular Respiration Efficiency:
Only about 34% efficient (34% of potential E in glucose is transferred to ATP)
Actually pretty efficient (good cars are only 25%)
The rest of the energy is lost as heat
Some is used to maintain high body temps (human)
Rest is dissipated through sweating or other cooling mechanisms