1. C-9-3 Cellular Respiration

2. Cellular Respiration: Chemical Pathways Cellular Respiration – the process that releases ENERGY by breaking down GLUCOSE in the presence of OXYGEN.

3. 3 main stages GLYCOLYSIS (in the cytoplasm) KREBS CYCLE (in mitochondria) ELECTRON TRANSPORT CHAIN (in the inner membrane of the mitochondria)

4. Each of the three stages captures some of the chemical energy available in FOOD molecules and uses it to produce ATP. ATP – HIGH ENERGY molecule that the cell can us for an energy source ADP – LOW ENERGY molecule

5. Cellular Respiration Oxygen + glucose ---> carbon dioxide + water + energy

7. 1st stage: GLYCOLYSIS - “to break apart glucose”

8. Glycolysis Takes place in the CYTOPLASM of the animal cell One molecule of GLUCOSE (6 C’s) is broke in half to make 2 PYRUVIC ACID molecules (3 C’s each) 2 ATP molecules are used up in the beginning of glycolysis in order to break apart the glucose molecule When glycolysis is complete 4 ATP molecules are produced (net gain of 2 ATP molecules)

9. Glycolysis NAD+- an electron carrier involved in glycolysis NADH - reduced form of NAD+ (NAD+ turns into NADH when it receives electrons)

10. Glycolysis 4 high energy ELECTRONS are removed during glycolysis and passed to NAD+ When electrons get passed to NAD+ it changes to NADH NADH holds electrons until they can be transferred to other molecules (THEN it goes to the electron transport chain)

11. FERMENTATION - releases energy from food molecules by producing ATP in the absence of oxygen Because fermentation does NOT require oxygen it is said to be ANAEROBIC

12. Alcoholic Fermentation Pyruvic acid + NADH --->alcohol + carbon dioxide + NAD+ Produces ALCOHOLIC FERMENTATION and CARBON DIOXIDE

13. Yeast – causes bread dough to rise; when yeast runs out of oxygen it begins to ferment giving off bubbles of CARBON DIOXIDE that forms the holes you see in a slice of bread (the alcohol evaporates when its baked) Beer and wine and other alcoholic beverages use this process

14. Lactic Acid Fermentation Pyruvic acid + NADH --->lactic acid + NAD+ Produces LACTIC ACID Lactic acid is produced in your MUSCLES during rapid EXERCISES when the body cannot supply enough oxygen to the tissues

15. Without enough oxygen, the body can’t produce the ATP that is required so lactic acid fermentation allows NAD+ to be produced so glycolysis continues *Your muscles can get SORE quickly because of the build-up of lactic acid in the muscle cells *This process is also used by unicellular organisms to produce foods such as cheese, yogurt, sour cream, pickles, and sauerkraut.