Download Ch 9 Notes Cellular Respiration: Harvesting Chemical Energy

Ch 9 Notes.
Cellular Respiration:
Harvesting Chemical Energy
Re-dox reactions:
Reduction/Oxidation rxns.
Basically a transfer of electrons
from something less
electronegative to something
more electronegative.
Molecules release energy when
this happens. Oxygen is very
electronegative, so it acts like
an electron magnet.
LEO = Lose Electrons
Oxidation
GER = Gain Electrons
Reduction
So how do we capture the
energy released?
We use a series of reactions
called cellular respiration:
Glycolysis, Kreb’s Cycle,
Electron Transport Chain
(ETC).
Glycolysis (Splitting a sugar)
Takes place in the cytosol.
No Oxygen necessary. Uses
enzymes.
Goes in: Glucose + 2ATP
Comes out: 4 ATP + 2
NADH + 2 Pyruvates.
Kreb’s Cycle: Discovered by
Hans Kreb’s, 1930. Basically,
it’s a series of reactions that
remove electrons from the sugar
(what’s left of them).
We are now entering the
mitochondria
Goes in: Pyruvate (converted to
Acetyl Co-A), NAD+, FAD.
Comes out: CO2 , 6NADH,
2FADH2, 2ATP
Electron Transport Chain
(ETC): A series of molecules
embedded in the inner
membrane of the mitochondria.
Electron Transport Chain
What goes in: 10 NADH, 2
FADH2, lots of ADP, Oxygen
What comes out: ~34ATP,
NAD+, FAD, H2O
Fermentation: 2 main
pathways. Lactic Acid/Alcohol
Fermentation. Use glycolysis
(the start of both fermentation
and cellular respiration).
Fermentation doesn’t use
Oxygen. Anaerobic organisms
can use fermentation (yeast,
bacteria).
Pyruvate instead of going to the
Kreb’s cycle, gets turned into
alcohol or lactic acid.