KEY CONCEPT The overall process of cellular respiration converts sugar into ATP using oxygen.

Cellular respiration is an aerobic process with two main stages.

Cellular respiration makes ATP by breaking down sugars. Cellular respiration is aerobic, or requires oxygen. Aerobic stages take place in mitochondria. mitochondrion animal cell

Glycolysis must take place first. 1.takes place in cytoplasm 2.two ATP molecules are used to split glucose 3.four ATP molecules are produced 4.two molecules of electron carrier (NADH) produced 5.two molecules of pyruvate produced pyruvate (net)

–Gycolysis is an anaerobic process (does not require oxygen). –Cellular respiration is aerobic, or requires oxygen. The products of glycolysis enter cellular respiration when oxygen is available.

Aerobic stages take place in mitochondria. mitochondrion animal cell

The first step of cellular respiration is the Krebs Cycle: 1.Pyruvate molecules from glycolysis enter 2.pyruvates are broken down in mitochondrial matrix 3.releases carbon dioxide as waste 4.makes 2 ATP and electron carriers (NADH and FADH 2 ) that transfer energy to an electron transport chain 6H O 2 6CO 2 6O 2 mitochondrion matrix (area enclosed by inner membrane) inner membrane ATP energy energy from glycolysis and Krebs Cycle

1.takes place in inner membrane (cristae) where oxygen enters process 2.Uses NADH and FADH 2 to make ATP in the mitochondrial membrane. The electron transport chain produces a large amount of ATP. 6H O 2 6CO 2 6O 2 mitochondrion matrix (area enclosed by inner membrane) inner membrane ATP energy energy from glycolysis and

3.ATP synthase produces ATP 4.water is released as a waste product The breakdown of one glucose molecule produces up to 36 molecules of ATP.

Cellular respiration makes up to 38 ATP from 1 glucose (2 from glycolysis, 2 from Krebs Cycle, and from electron transport chain).

The equation for the overall process is: C 6 H 12 O 6 + 6O 2  6CO 2 + 6H 2 O + energy The reactants in photosynthesis are the same as the products of cellular respiration.

Glycolysis is needed for cellular respiration. The products of glycolysis enter cellular respiration when oxygen is available (aerobic). – Reactants: 2 ATP, glucose – Products: 4 ATP, 2 NADH, 2 pyruvate molecules

KEY CONCEPT Fermentation allows the production of a small amount of ATP without oxygen.

Fermentation allows glycolysis to continue. Fermentation allows glycolysis to continue making ATP when oxygen is unavailable (anaerobic). Fermentation does not make ATP.

Lactic acid fermentation occurs in muscle cells. –pyruvate and NADH enter fermentation –energy from NADH converts pyruvate into lactic acid –Occurs in muscle cells during intense exercise –Also used to make cheese and yogurt

Alcoholic fermentation is similar to lactic acid fermentation. – glycolysis splits glucose and the products enter fermentation –energy from NADH is used to split pyruvate into an alcohol and carbon dioxide –NADH is changed back into NAD + –NAD + is recycled to glycolysis

Fermentation is used in food production. –yogurt –cheese –Bread

Aerobic vs Anaerobic Cellular Respiration Aerobic cellular respiration Adv: produces 36 ATP, long term energy supply Adv: produces 36 ATP, long term energy supply Disadv: requires oxygen, slower process Disadv: requires oxygen, slower process Anaerobic cellular respiration (fermentation) Adv: no oxygen, happens quick Disadv: only 2 ATP, muscle soreness