AP BIO NOTES (copy)

Aerobic Respiration

Requires oxygen as a reactant and releases more energy through the complete oxidation of glucose; can produce up to 32 ATP per glucose molecule.

Anaerobic Respiration

Does not require oxygen and uses other compounds as final electron acceptors; produces less energy compared to aerobic respiration.

Glycolysis

The process that breaks down one 6-carbon glucose molecule into two 3-carbon pyruvate molecules, occurring in the cytosol.

Energy Input of Glycolysis

Requires 2 ATP to initiate the glycolysis process.

Energy Output of Glycolysis

Produces 4 ATP, resulting in a net gain of 2 ATP.

NADH Generation in Glycolysis

Generates 2 NADH through reduction-oxidation reactions during glycolysis.

Transition Step

Converts each pyruvate to Acetyl CoA, producing 2 NADH and releasing 2 CO2 before entering the Krebs cycle.

Krebs Cycle

Occurs in the mitochondrial matrix where Acetyl CoA combines with oxaloacetate to form citrate and produces energy carriers.

Energy Output of Krebs Cycle

Produces 3 NADH, 1 FADH2, and 1 ATP per Acetyl CoA (double for glucose).

Electron Transport Chain (ETC)

Occurs in the inner mitochondrial membrane where NADH and FADH2 donate electrons, ultimately reducing O2 to form water.

Proton Gradient in ETC

Energy is released as electrons move through complexes I-IV, creating a proton gradient across the inner membrane.

ATP Synthase Mechanism

ATP synthase undergoes a conformational change powered by the proton motive force, leading to phosphorylation of ADP to ATP.

Fermentation Location

Occurs in the cytosol when oxygen is not available.

Alcoholic Fermentation

Converts pyruvate to ethanol and CO2, typically occurring in yeast.

Lactic Acid Fermentation

Converts pyruvate to lactate, typically occurring in muscle cells.

Energy Yield of Fermentation

Produces 2 ATP from glycolysis and allows for regeneration of NAD+ so glycolysis can continue.

Fuel Sources for Cellular Respiration

Carbohydrates, fats, and proteins can all enter cellular respiration at various points.

Regulation of Cellular Respiration

Allosteric enzymes regulate glycolysis and the citric acid cycle; inhibited by high levels of ATP and citrate, stimulated by AMP.

Order of Steps in Cellular Respiration

The sequence of steps is Mitochondrion, Glycolysis, Krebs Cycle, Electron Transport Chain, and Fermentation