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Cellular Respiration. Cellular Respiration. Cellular respiration releases chemical energy from sugars and other carbon-based molecules to make ATP . It is an aerobic process. needs oxygen to take place. Cellular Respiration. Cell respiration takes place in the mitochondria .
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Cellular Respiration • Cellular respiration releases chemical energy from sugars and other carbon-based molecules to make ATP. • It is an aerobic process. • needs oxygen to take place.
Cellular Respiration • Cell respiration takes place in the mitochondria. • Foods are broken down into small molecules like glucose. • Glucose is broken down during glycolysis.
Glycolysis • Glycolysis • Takes place BEFORE cell respiration. • Splitsthe glucose molecule into two three-carbon molecules (pyruvates) and makes two molecules of ATP. • It takes place in the cytoplasm of the cell. • It is an anaerobicprocess. • Does NOT require oxygen to take place.
Krebs Cycle • The first part of cellular respiration. • Sometimes called the citric-acid cycle. • Producesmolecules that carry energy to the second part of cellular respiration. (NADH and FADH2) • Takes place in the interior space (matrix) of the mitochondria.
Krebs Cycle 1. Pyruvate broken down. • Pyruvate is split into 3 molecules of carbon Dioxide which are given off as waste • 4 molecules of NADH and one FADH2 form. • They will move to the electron transport chain.
Krebs Cycle Products • The Krebs cycle will break down TWO pyruvate molecules at the same time. • Products: • 6 carbon dioxide molecules. • 2 molecules of ATP • 8 molecules of NADH • Will go to the electron transport chain. • 2 molecules of FADH2 • Will go to the electron transport chain.
Electron Transport Chain • Second part of cellular respiration. • Energy from the Krebs cycle (NADH and FADH2) is transferred to a chain of proteins in the inner membrane of the mitochondrion. • A large number of ATP molecules are made. • Oxygen is used to make water molecules. • Water and heat are given off as a waste
Electron Transport Chain 1. Electrons removed. • Proteins inside the mitochondrion take high-energy electrons from NADH and FADH2. • Two molecules of NADH and one of FADH2 are used. 2. Hydrogen ions transported. • Hydrogen ions are built up along the inner mitochondrial membrane using energy from the electrons.
Electron Transport Chain Products • For EACH molecule of glucose the ETC can make: • Up to 34 molecules of ATP
Cellular Respiration Products • Up to 38 ATP are made from the breakdown of ONE glucose molecule. • 2 ATP from glycolysis • 36 ATP from cellular respiration (Krebs - 2) Cycle and Electron Transport Chain - 34) • Other products include carbon dioxide and water. • The equation for cellular respiration is: • C6H12O6 + 6O2 6CO2 + 6H2O
Fermentation • Fermentation is an anaerobic process that takes place when there is less oxygen in the body (i.e. during strenuous activity) • Fermentation does NOT make ATP, but it allows glycolysis to continue. • Glycolysis needs NAD+ to pick up electrons when it splits glucose into pyruvate. • Fermentation removed electrons from NADH molecules and recycles NAD+ molecules for glycolysis.
Lactic Acid Fermentation in Animals 1. Pyruvate and NADH from glycolysis enter fermentation. • Two NADH molecules are used to convert pyruvate into lactic acid. • As the NADH is used, it converts back to NAD+. 2. TWO molecules of NAD+ are recycled back to glycolysis. • This allows your body to continue to break down sugar for energy!
Alcoholic Fermentation in Plants 1. Pyruvate and NADH from glycolysis enter alcoholic fermentation. • The NADH molecules provide energy to break pyruvate into alcohol and carbon dioxide. • As the NADH are used, they are converted to NAD+. 2. The molecules of NAD+ are recycled back to glycolysis. • The recycling of NAD+ allows glycolysis to continue.
Cellular Respiration and Photosynthesis • Cellular Respiration and Photosynthesis are approximately the reverse of each other. • Photosynthesis stores energy. • Cellular Respiration releases it.
