CELLULAR RESPIRATION Chapter 9

Cellular Respiration The process that releases energy by breaking down glucose and other food molecules in the presence of oxygen.  6 O 2 + C 6 H 12 O 6  6 CO H 2 O + Energy oxygen + Glucose  carbon + water + energy dioxide  Uses energy to produce ATP  Aerobic – requires oxygen  Occurs in the mitochondria

Fermentation Fermentation – releases energy from food molecules by producing ATP in the absence of oxygen  Anaerobic – does not require oxygen 1. Alcoholic Fermentation  Used by yeast and other microscopic organisms  Produces CO 2 and alcohol  Causes bread dough to rise

Fermentation cont. 2. Lactic Acid Fermentation  Produces lactic acid  Produced in your muscles during rapid exercise when the body cannot supply enough oxygen to the tissues.  Causes muscles to feel a painful, burning sensation

Glycolysis The first set of reactions in cellular respiration. Does not require oxygen. Uses 2 ATP molecules during the process, but produces 4 ATP molecules. This gives the cell a net gain of 2 ATP molecules. Glucose is broken down into 2 molecules of pyruvic acid.

Glycolysis cont. Captures two pairs of electrons with the carrier NAD +. NADH holds the electrons until they can be transferred to other molecules.

Comparing Photosynthesis and Cellular Respiration PhotosynthesisCellular Respiration FunctionCaptures energyReleases energy LocationChloroplastsMitochondria ReactantsCO 2 + H 2 OC 6 H 12 O 6 + O 2 ProductsC 6 H 12 O 6 + O 2 CO 2 + H 2 O Occurs inAutotrophs onlyBoth Autotrophs and Heterotrophs Photosynthesis and Cellular Respiration are opposites of each other.