Ap Bio Chapter 9 Outline

Ap Bio Chapter 9 Outline AP Biology Chapter 9 Cellular Respiration and Fermentation I Life requires energy Living organisms are complex systems that require a constant input of energy to maintain their organization grow and reproduce This energy is derived from the breakdown of food molecules Cellular respiration is the process by which cells harvest energy from food molecules It is a series of metabolic reactions that convert the chemical energy stored in organic molecules into a form that can be used by the cell primarily ATP adenosine triphosphate Fermentation is a less efficient energyyielding process that occurs when oxygen is limited It uses organic molecules as electron acceptors instead of oxygen II Catabolic Pathways and the Production of ATP Catabolic pathways are metabolic pathways that break down complex molecules into simpler ones releasing energy Cellular respiration is a major catabolic pathway ATP is the primary energy currency of cells It is a nucleotide composed of adenine ribose and three phosphate groups Phosphorylation is the process of adding a phosphate group to a molecule ATP hydrolysis breaking down ATP releases energy that can be used to power cellular work III Cellular Respiration Four Stages 1 Glycolysis Occurs in the cytoplasm Breaks down glucose into pyruvate a 3carbon molecule Produces a small amount of ATP and NADH a reduced electron carrier Does not require oxygen 2 Pyruvate Oxidation Occurs in the mitochondrial matrix Converts pyruvate into acetylCoA releasing CO2 Produces NADH 3 Citric Acid Cycle Krebs Cycle Occurs in the mitochondrial matrix Oxidizes acetylCoA to CO2 2 Generates ATP NADH FADH2 another reduced electron carrier and other metabolic intermediates 4 Oxidative Phosphorylation Occurs in the inner mitochondrial membrane Uses the electron transport chain to move electrons from NADH and FADH2 to oxygen releasing energy This energy is used to pump protons across the inner mitochondrial membrane creating a proton gradient ATP synthase uses the proton gradient to synthesize ATP IV Electron Transport Chain and Chemiosmosis Electron transport chain A series of protein complexes embedded in the inner mitochondrial membrane Electrons are passed from one complex to the next releasing energy This energy is used to pump protons across the membrane creating a proton gradient Chemiosmosis The movement of protons down their concentration gradient from high concentration to low concentration across the membrane This movement powers ATP synthase which generates ATP from ADP and phosphate V Anaerobic Respiration Anaerobic respiration occurs in the absence of oxygen Some organisms use other molecules such as sulfate or nitrate as electron acceptors in place of oxygen Anaerobic respiration is less efficient than aerobic respiration but it allows certain organisms to survive in environments lacking oxygen VI Fermentation Fermentation is a metabolic process that occurs in the absence of oxygen It uses organic molecules as electron acceptors instead of oxygen Lactic acid fermentation Occurs in muscle cells during strenuous exercise Pyruvate is reduced to lactate regenerating NAD for glycolysis Alcoholic fermentation Occurs in yeast and some bacteria Pyruvate is converted to ethanol and CO2 regenerating NAD for glycolysis VII Regulation of Cellular Respiration Cellular respiration is tightly regulated to ensure an adequate supply of ATP while minimizing 3 wasteful energy expenditure Feedback mechanisms Products of cellular respiration can inhibit or activate specific enzymes in the pathway Allosteric regulation Molecules bind to enzymes at sites other than the active site altering their activity VIII Importance of Cellular Respiration Cellular respiration is essential for life It provides the energy required for Growth and development Movement and locomotion Cellular communication Synthesis of macromolecules Maintenance of body temperature Cellular respiration also plays a crucial role in the global carbon cycle consuming oxygen and producing CO2 IX Applications of Cellular Respiration Biotechnology Understanding cellular respiration has led to advances in areas such as Biofuel production Industrial fermentation processes Medical treatments for metabolic disorders Environmental science Cellular respiration is fundamental to understanding the balance of gases in the atmosphere and the carbon cycle X Conclusion Cellular respiration is a complex and highly efficient process that allows organisms to extract energy from food molecules Understanding its mechanism is crucial for comprehending the fundamental principles of life and its applications in various fields This chapter provides a framework for exploring the intricacies of this vital process Note This outline is a concise summary of the key concepts in Chapter 9 It is recommended to refer to your textbook and other resources for more detailed information and examples 4