Transcript Ch. 9 Cellular Respiration

Ch. 9 Cellular Respiration
Harvesting Chemical Energy
9.1 Catabolic pathways yield energy by
oxidizing organic fuels
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Can be aerobic or anaerobic
Cellular respiration vs fermentation
Energy released is used to do work and some
is lost as heat
ATP is produced
Oxidation and Reduction
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The relocation of electrons releases energy stored in
organic molecules
Leo goes ger – lose electron/oxidation, gain
electron/reduction(reduction in positive charge)
Oxidizing vs Reducing agent
https://www.youtube.com/watch?v=ZwU8xY5VnQk
Oxidation of organic fuel
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Glucose is oxidized and oxygen is reduced
Electrons lose potential energy along the way
and energy is released
Enzymes in our cells allow glucose to be
oxidized in a series of steps
Stepwise Energy Harvest via NAD+
Electron Transport Chain
The Stages of Cellular Respiration
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3.
Glycolysis
Citric Acid Cycle
Oxidative phosphorylation: electron transport
and chemiosmosis
Overview of cellular respiration
Substrate-level phosporylation
9.2 Glycolysis
A Closer Look at Glycolysis
9.3 Citric Acid Cycle
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Much of the energy remains in the pyruvate
molecules
If oxygen is present, pyruvate enters
mitochondrion and oxidation is completed by
enzymes of the CAC
But first we must convert pyruvate to Acetyl
CoA
Conversion of pyruvate to acetyl CoA
A closer look at the citric acid cycle
The Pathway of Electron Transport
Electron Transport Animation
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http://highered.mheducation.com/sites/007250
7470/student_view0/chapter25/animation__el
ectron_transport_system_and_atp_synthesis_
_quiz_1_.html
http://vcell.ndsu.nodak.edu/animations/atpgra
dient/movie-flash.htm
Fermentation
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Glycolysis plus a mechanism to regenerate
NAD+ from NADH
1. Alcoholic fermentation – pyruvate is
converted to ethyl alcohol plus carbon dioxide
2. Lactic Acid fermentation – pyruvate is
converted to lactic acid
Obligate vs facultative anaerobes
Lactic vs alcoholic fermentation
The Evolutionary Significance of
Glycolysis
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Glycolysis is the most widespread metabolic
pathway among Earth’s organisms
The cytosolic location of glycolysis implies
great antiquity
http://ed.ted.com/on/qUVJINlN
Glycolysis and the citric acid cycle connect
to many other metabolic pathways
Biosynthesis
Regulation of Cellular Respiration via feedback
mechanisms