Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings The Big Picture
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Breathing and cellular respiration are different, but closely related processes
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings oxygen strips all the hydrogen atoms from glucose. “stripped glucose” is carbon dioxide! “hydrogenated oxygen” is water!
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings glucose is oxidized to CO 2 oxygen is reduced to H 2 O the simultaneous loss and gain of hydrogens is called a “redox’” reaction.
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
When something combusts, O 2 is reduced in one explosive step. Energy released as heat and light
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Mary Reeser July 2, 1951 St. Petersburg, Florida
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Oxidation is the removal of electrons from carbon. The molecule that takes these electrons is simultaneously reduced. Coupled together, these are redox (oxidation/reduction) reactions.
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings NADH passes its electrons to O 2
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Three parts to respiration
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Review Exergonic reactions “push” or “drives” endergonic reactions. The exergonic “burning” of the sun drives endergonic ADP phosphorylation. When a match burns, glucose is oxidized to CO 2 ; oxygen is reduced to water. Respiration is essentially the same process, but it occurs stepwise in the cell. NAD and FAD are intermediate carriers of electrons (hydrogen atoms) to oxygen. Respiration is composed of three parts –Glycolysis (in the cytoplasm) –Citric acid cycle (in the mitochondrion) –Oxidative phosphorylation and chemiosmosis (in and across the inner mitochondrial membrane)
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings GLYCOLYSIS
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Substrate-level phosphorylation
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Grooming pyruvate for the citric acid cycle
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings CITRIC ACID CYCLE
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Sir Hans Krebs ( )
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
ELECTRON TRANSPORT SYSTEM
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FERMENTATION: ATP without oxygen Electron transport
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings LACTIC ACID “FERMENTATION” Electron transport
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Long-distance runners have many slow twitch (type I) muscle fibers –Slow fibers break down glucose for ATP production aerobically (using oxygen) –More mitochondria and myoglobin –These muscle cells can sustain repeated contractions for a long time. How is a Marathoner Different from a Sprinter?
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Sprinters have more fast twitch (type II) muscle fibers –Fast fibers make ATP without oxygen— anaerobically –More lactate-producing enzymes (LDH) –They can contract quickly and supply energy for short bursts of intense activity
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings The dark meat (myoglobin) of a cooked turkey is an example of slow fiber muscle The white meat consists of fast fibers
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Catabolism
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Anabolism
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Negative and positive feedback to allosteric enzymes control the rate of respiration.
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings (a)Glycolysis (b)Citric acid cycle (c)Oxidative phosphorylation (d)Oxygen (e)Electron transport chain (f)Carbon dioxide and water