Overview of Cellular Respiration Link to Summas

Figure 9.6 An overview of cellular respiration (Layer 1)

Figure 9.6 An overview of cellular respiration (Layer 2)

Figure 9.6 An overview of cellular respiration (Layer 3)

CELLULAR RESPIRATION OVERALL REACTION: C6H12O6 + 6 O2 -> 6 CO2 + 6 H2O Link to Overall Rxn Animation Link to Glycolysis Animation

GLYCOLYSIS Simplest ATP production pathway, present in essentially all cells Most likely evolved very early in cell development Has 2 main phases: ENERGY INVESTMENT AND ENERGY PAYOFF

Figure 9.8 The energy input and output of glycolysis

Figure 9.9 A closer look at glycolysis: energy investment phase (Layer 2)

Figure 9.9 A closer look at glycolysis: energy payoff phase (Layer 4)

Figure 9.7 Substrate-level phosphorylation

Ethanol or lactate Citric acid cycle Fig. 9-19 Glucose Glycolysis CYTOSOL Pyruvate O2 present: Aerobic cellular respiration No O2 present: Fermentation MITOCHONDRION Ethanol or lactate Acetyl CoA Citric acid cycle

ANAEROBIC PATHWAYS How does the cell regenerate NAD+ to continue glycolysis in the absence of O2?

Fig. 9-18 2 ADP + 2 Pi 2 ATP Glucose Glycolysis 2 Pyruvate 2 NAD+ 2 NADH 2 CO2 + 2 H+ 2 Ethanol 2 Acetaldehyde (a) Alcohol fermentation 2 ADP + 2 Pi 2 ATP Glucose Glycolysis 2 NAD+ 2 NADH + 2 H+ 2 Pyruvate 2 Lactate (b) Lactic acid fermentation

Link to alcohol anaerobic respiration Link to lactic acid anaerobic respiration

(a) Alcohol fermentation Fig. 9-18a 2 ADP + 2 P 2 ATP i Glucose Glycolysis 2 Pyruvate 2 NAD+ 2 NADH 2 CO2 + 2 H+ 2 Acetaldehyde 2 Ethanol (a) Alcohol fermentation

(b) Lactic acid fermentation Fig. 9-18b 2 ADP + 2 P 2 ATP i Glucose Glycolysis 2 NAD+ 2 NADH + 2 H+ 2 Pyruvate 2 Lactate (b) Lactic acid fermentation