VI. Anaerobic Respiration This process occurs when oxygen is NOT available to produce ATP. This process occurs when oxygen is NOT available to produce ATP. OR FOR ORGANISMS THAT DON’T NEED AS MUCH ENERGY!

A. 2 Stages to ANaerobic CR 1. Glycolysis – 1 st stage (same as normal CR) a. Reactant: Glucose a. Reactant: Glucose b. Products: 2 ATP 2 NADH 2 NADH 2 pyruvic acid 2 pyruvic acid 2. Fermentation- 2 nd stage. occurs instead of Krebs and ETC when NO oxygen is available.

B. No oxygen available so: 1. No free NAD+ molecules in the cell 2. Fermentation does NOT produce ATP. 2. Fermentation does NOT produce ATP. (The only ATP from anaerobic respiration is from glycolysis!) A. It changes NADH- to NAD+, so glycolysis can continue..

C. Two types of fermentation: 1. Alcoholic 1. Alcoholic 2. Lactic Acid

D. Alcoholic Fermentation 1. Only bacteria and yeast use this 2. Reactants: Pyruvic acid and NADH (from glycolysis) 3. Products: a. alcohol (2 carbon molecule) a. alcohol (2 carbon molecule) b. carbon dioxide b. carbon dioxide c. NAD+ 4. EQUATION: pyruvic acid + NADH  alcohol +CO 2 + NAD + pyruvic acid + NADH  alcohol +CO 2 + NAD + 5. Used in baking and alcohol industries

Yeast Alcoholic Fermentation Alcoholic Fermentation CO 2 bubbles CO 2 bubbles CO2 bubbles make Bread rise and make bubbles in beer

E. Lactic Acid Fermentation 1. Takes place in: a. skeletal muscle cells during vigorous exercise i. muscles can’t get oxygen fast enough for aerobic CR ii. creates burning and soreness ii. creates burning and soreness in muscles during and after exercise. in muscles during and after exercise.

b. In the food industry, bacteria use lactic acid to make: i. dairy products ii. pickled products ii. pickled products

The NAD+ allows glycolysis to happen again.

4. Reactants: Pyruvic Acid and NADH (from glycolysis) 5. Products: Lactic acid and NAD+ 6. EQUATION: Pyruvic acid + NADH  lactic acid + NAD +

Comparing Aerobic CR Anaerobic Fermentation CR Anaerobic Lactic Acid CR

Aerobic 1. Cell type- body cells under normal conditions 2. Reactants- glucose and oxygen 3. Products- carbon dioxide and water Energy- 36 ATP’s Energy- 36 ATP’s 4. 3 STAGES: Glycolysis, Krebs cycle, ETC

Anaerobic-Alcohol Fermentation 1. Cell type- Bacteria and yeast 2. Reactant- glucose 3. Products- Alcohol, carbon dioxide and NAD+ Energy – 2 ATP- FROM GLYCOLYSIS NOT FERMENTATION Energy – 2 ATP- FROM GLYCOLYSIS NOT FERMENTATION 4. 2 STAGES: Glycolysis, Alcoholic fermentation

Anaerobic Lactic Acid 1. Cell type- muscle cells when no oxygen available (and bacteria) 2. Reactant- glucose 3. Products- lactic acid and NAD+ Energy – 2ATP – FROM GLYCOLYSIS NOT ERMENTATION! 4. 2 STAGES: Glycolysis, Lactic acid fermentation