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Cellular Respiration Part 3. Krebs Cycle – Pages 96 to 97. Chemically Grooming Pyruvate. 3 steps to Krebs Cycle Carbon atom is removed (3C to 2C) and released as CO2 2C compound is oxidized while NAD+ is reduced to NADH Coenzyme A joins with 2C to form acetyl co-A. Fig. 9-10. CYTOSOL.
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Cellular Respiration Part 3 Krebs Cycle – Pages 96 to 97
Chemically Grooming Pyruvate • 3 steps to Krebs Cycle • Carbon atom is removed (3C to 2C) and released as CO2 • 2C compound is oxidized while NAD+ is reduced to NADH • Coenzyme A joins with 2C to form acetyl co-A
Fig. 9-10 CYTOSOL MITOCHONDRION NADH + H+ NAD+ 2 1 3 Acetyl CoA Coenzyme A Pyruvate CO2 Transport protein
Krebs Cycle (Citric Acid Cycle) • Called the Citric Acid Cycle because Citric Acid (citrate) is the 1st molecule formed in the cycle • Called the Krebs Cycle after Hans Krebs – the researcher who discovered it • Occurs in the matrix of the mitochondria • Involves 2 electron carriers – NADH and FADH2 • The cycle oxidizes organic fuel derived from pyruvate, generating 1 ATP, 3 NADH, and 1 FADH2 per turn
Fig. 9-11 Pyruvate CO2 NAD+ CoA NADH + H+ Acetyl CoA CoA CoA Citric acid cycle 2 CO2 FADH2 3 NAD+ NADH 3 FAD + 3 H+ ADP + P i ATP
Summary of Krebs Cycle • 2C of acetyl Co-A joins with 4C of OAA to form 6C citrate; Co-A is recycle • Thru a series of energy extracting reactions 2CO2, 3NADH, 1FADH2 + 1 ATP are produced per turn • Remaining 4C molecule is rearranged to form OAA
Fig. 9-12-8 Products for 1 glucose including grooming: 8 NADH 2 FADH2 2 ATP 6 CO2 Acetyl CoA Products for 1 turn including grooming: 4 NADH 1 FADH2 1 ATP 3 CO2 CoA—SH NADH H2O 1 +H+ NAD+ Oxaloacetate 8 2 Malate Citrate Isocitrate NAD+ Citric acid cycle NADH 3 + H+ 7 H2O CO2 Fumarate CoA—SH -Keto- glutarate 4 6 CoA—SH 5 FADH2 CO2 NAD+ FAD Succinate NADH P i + H+ Succinyl CoA GDP GTP ADP ATP