Cellular Respiration – process that releases energy Cellular Respiration – process that releases energy from food (chemical energy) in the presence of oxygen. Glucose  Energy The Overall Reaction: In Words:

The Process of Cell Respiration occurs in 3 Stages Stage 1: Glycolysis Need to know Occurs in the Cytoplasm of the Cell Starts with: 1 Glucose molecule Investment of 2 ATP. Produces with: A net gain of 2 ATP is made 2 NADH travels to the E.T.C. 2 Pyruvic Acids are made

Stage 2: Krebs Cycle Need to Know Occurs in the Matrix of the Mitochondria. 2 Turns of the Cycle (1 per Pyruvic Acid) Process Requires the presence of Oxygen Starts with: 2 Pyruvic Acids Produces: 2 ATP (1 per Pyruvic Acid) CO2 is produced (Waste Product) NADH and FADH2 carry electrons to the E.T.C.

Stage 3: Electron Transport Chain Need to Know Occurs in the Intermembrane Space of the Mitochondria. Starts with: Oxygen is required High Energy Electrons carried by NADH and FADH2, (acquired in Glycolysis and the Krebs Cycle). Produces: 32 ATP Water Molecules

2 ATP 2 ATP 32 ATP Cytoplasm  (Net Gain) The Matrix  (1 per Pyruvic Acid) Intermembrane Space  32 ATP

Photosynthesis and Cellular Respiration can be thought of as opposite reactions. The reactants for one become the products of the other.

9.3 Fermentation Cellular Respiration is sometimes called Aerobic Respiration. Aerobic means “With Air” or in the presence of Oxygen. Respiration can also occur in the absence of Oxygen as well. This is called Anaerobic Respiration. (No Air) Without Oxygen, the Pyruvic Acids produced during Glycolysis cannot enter the Krebs Cycle. Instead, an alternative process called Fermentation can occur in order to continue the breakdown and create ATP.

There are two types of Fermentation: Alcoholic Fermentation (performed by yeast cells) Lactic Acid Fermentation (performed by muscle cells)