Cellular Respiration - the opposite of photosynthesis Sugar + Oxygen Carbon Dioxide + Water + Energy C 6 H 12 O 6 + 6O 2 6C O 2 + 6H 2 O + Energy Glycolysis- Sugar cutting – breaking down of sugar

Organic Compounds Glycolysis Fermentation Aerobic Respiration ATP Lactic AcidEthyl Alcohol

Overview of cellular respiration

Cellular Respiration Glycolysis –Anaerobic –Aerobic

Cellular Respiration The process by which animals break down organic compounds (sugar) and turn them into ATP (Energy)

Glycolysis Glyco – refers to Glucose Lysis – to loosen (break apart) Glycolysis – is the breaking apart of glucose –produces only 2 ATP –Happens in the cytosol of the cell –Leads to aerobic or anaerobic respiration

Four steps in Glycolysis Step one Two phosphate groups are attached to glucose, forming a new six carbon compound. The Phosphate groups are donated by ATP. Two ATP used in this step

Second Step in Glycolysis The six carbon compound formed in step one is split into two three carbon molecules PGAL

Third Step in Glycolysis Two PGAL molecules are oxidized and each receives a phosphate group. The product of this step is two molecules of NAD + to NADH. NAD + or nicotinamide adenine dinucleotide, is very similar to NADP + a compound you encountered in the light reactions of photosynthesis. NAD + is an organic molecule that accepts electrons during redox reactions

Fourth Step in Glycolysis The phosphates added in step one and three are removed from the three carbon compound formed in step 3, This reaction produces two molecules of Pyruvic acid Four ATP produced in this step

Anaerobic Respiration Also known as anaerobic fermentation No oxygen present No ATP produced Two common fermentation pathways result in the formation of lactic acid and ethyl alcohol

Lactic Acid Fermentation Glucose Pyruvic Acid Lactic Acid NAD + NADH + H + Glycolysis

Alcoholic Fermentation Glucose Pyruvic Acid Ethyl Alcohol NAD + NADH + H + Glycolysis 2- Carbon compound

Efficiency of Glycolysis Is 3.5% Energy Required to make ATP Energy Released by oxidation of glucose