Cellular Respiration Harvesting Chemical Energy 6H2O + 6CO2 + Energy C6H12O6 + 6O2 Cellular Respiration Harvesting Chemical Energy

Steps in Respiration glycolysis breakdown of pyruvic acid (prep for C-A-C) citric acid cycle (C-A-C) electron transport chain **steps 2 and 3 are sometimes referred to as the Kreb’s Cycle

Glycolysis glucose is split into two molecules of pyruvic acid (pyruvate) Anaerobic process occurs in cytoplasm Produces 4 molecules of ATP, but uses 2 ATP net gain = 2 ATP

Glycolysis Splits a glucose molecule into 2 - 3 Carbon molecules called PYRUVATE. products: 2 ATP, NADH and pyruvate

The Citric Acid Cycle Products: CO2, ATP, NADH, FADH

Products of the Electron Transport Chain 34-38 ATP + Water

ONE GLUCOSE MOLECULE PRODUCES 38 ATP Each NADH 3 ATP Each FADH 2 ATP Glycolysis (2 NADH) 6 ATP Prep for Citric Acid 6 ATP Citric Acid (6 NADH) 18 ATP (2 FADH2) 4 ATP 34 ATP direct 4 ATP total 38 ATP

Typically, a human will use up their body weight of ATP over the course of the day. This means that each ATP molecule is recycled 1000 to 1500 times during a single day. ATP cannot be stored, hence its consumption closely follows its synthesis.

Cells Recycle ATP

after glycolysis: if oxygen is present,  aerobic respiration no oxygen  anaerobic respiration (fermentation) 2 types of fermentation Alcoholic (occurs when baking- yeast breaks down sugar and produces CO2 and also producing alcohol) Lactic acid (occurs in your muscles)

Alcoholic Fermentation Some organisms carry out alcoholic fermentation. This was discovered by Louis Pasteur in his study of the chemistry of wines. Yeasts break down the sugars in the juice to pyruvate by glycolysis, then the pyruvate is dismantled to yeild CO2 and ETHANOL. If the fermentation continues until all the sugar is used, a dry wine is produced. If fermentation is stopped before all the sugar is used, then a sweet wine is produced.

Aerobic vs Anaerobic Respiration takes longer produces ~40 ATP (2 are used up, net gain is 38) Fermentation fast 2 ATP produced; only able to run glycolysis again (no net gain)

What happens when there is no oxygen to accept the electrons? Only the process of glycolysis is carried out and lactic acid is produced in the muscles. The body cannot tolerate much lactic acid and it must eventually be converted in the liver to pyruvate. results in muscle soreness