Cellular Respiration- the opposite of photosynthesis

Sugar + Oxygen Carbon Dioxide + Water + Energy

C6 H12O6 + 6O2 6C O2 + 6H2O + Energy

Glycolysis- Sugar cutting – breaking down of sugar

Organic Compounds

Glycolysis

Fermentation Aerobic Respiration

ATP

ATPLactic Acid Ethyl 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