Cellular Respiration The overall process of cellular respiration converts sugar into ATP using oxygen

C6H12O6 + 6O2  6CO2 + 6H2O The equation for the overall process The reactants in cellular respiration are the same as the products in photosynthesis

Ultimate goals of Cellular Respiration Convert chemical energy in nutrients to chemical energy in ATP ATP can then release energy for cellular processes Active transport Protein synthesis Muscle contraction

Nutrients + oxygen  water + energy (ATP) + carbon dioxide Any food or organic molecule (carbohydrates, proteins, lipids) can be processed and broken down as a source of energy for ATP molecules

Cellular Respiration makes ATP by breaking down sugars Cellular Respiration is aerobic, or requires oxygen Aerobic stages take place in the mitochondria To transfer energy stored in glucose to ATP molecule, a cell must break down glucose slowly and capture the energy stored in stages

Glycolysis Glycolysis must take place first Anaerobic process (does not require oxygen) Takes place in cytoplasm using enzymes

Glycolysis contd. Splits glucose into two three carbon molecules called pyruvic acid Produces 2 ATP molecules

Cellular Respiration is a mirror image of Photosynthesis The Krebs Cycle – 1st stage: **if oxygen is available Takes place in mitochondrial matrix Breaks down Pyruvic acid from glycolysis makes 2 ATP 6H O 2 6CO 6O mitochondrion matrix (area enclosed by inner membrane) inner membrane ATP energy energy from glycolysis 1 4 3 and

Krebs Cycle = Pyruvic Acid  carbon dioxide + water + energy (2 ATP) Releases carbon dioxide Transfers energy carrying molecules to electron transport chain 6H O 2 6CO 6O mitochondrion matrix (area enclosed by inner membrane) inner membrane ATP energy energy from glycolysis 1 4 3 and

The electron transport chain produces a large amount of ATP 6H O 2 6CO 6O mitochondrion matrix (area enclosed by inner membrane) inner membrane ATP energy energy from glycolysis 1 4 3 and Takes place in inner membrane of mitochondria Energy transferred to electron transport chain

Electron Transport Chain contd. Oxygen enters process ATP produced = up to 36 Water released as a waste product 6H O 2 6CO 6O mitochondrion matrix (area enclosed by inner membrane) inner membrane ATP energy energy from glycolysis 1 4 3 and

C6H12O6 + 6O2  6CO2 + 6H2O + energy Reactants: Glucose and oxygen used at different stages Products: Carbon dioxide and water also produced at different stages 34-36 ATP produced per glucose molecule

Fermentation Fermentation allows the production of a small amount of ATP without oxygen

Fermentation allows glycolysis to continue Makes ATP when oxygen is unavailable Anaerobic – occurs when oxygen is not available for cellular respiration Does not produce many ATP

Fermentation allows glycolysis to continue making ATP when oxygen is unavailable Fermentation is not an efficient process and results in the formation of far fewer ATP molecules than cellular respiration 2 types Lactic acid fermentation Alcoholic fermentation

Lactic Acid Fermentation Occurs in muscle cells Glycolysis splits glucose into 2 pyruvic acid molecules Pyruvic acid enters lactic acid fermentation and gets broken down into lactic acid

Glucose  Pyruvic Acid  Lactic acid + energy The process of lactic acid fermentation replaces aerobic respiration so that the cell can continue to have a source of energy even in the absence of oxygen Temporary, cells need oxygen for sustained activity Lactic acid builds up causing burning, painful sensation

Fermentation is used in food product Yogurt Cheese

Alcoholic Fermentation Similar to lactic acid fermentation Pyruvic acid from glycolysis enters fermentation and makes alcohol and carbon dioxide

Glucose  pyruvic acid  alcohol + carbon dioxide + energy Occurs in yeasts and some bacteria Yeast causes bread to rise Yeast breaks down sugars through glycolysis and alcoholic fermentation Alcohol evaporates into the air Holes in bread = CO2 bubbles