Overview of Cellular Respiration Process.pdf

9/3/24, 11:27 AM Overview of Cellular Respiration Process Catabolism 🔄 Catabolism is the process of breaking down complex molecules into simpler ones. Breaking down prote...

9/3/24, 11:27 AM Overview of Cellular Respiration Process Catabolism 🔄 Catabolism is the process of breaking down complex molecules into simpler ones. Breaking down proteins into amino acids Breaking down polysaccharides into monosaccharides Breaking down fats into fatty acids All of these will feed into the citric acid cycle and generate ATP for the cell. Cellular Respiration Equation C6 H12 O6 + 6O2 → 6CO2 + 6H2 O + energy ​ ​ ​ ​ ​ ​ Overview of Cellular Respiration This is an overview of all the steps of cellular respiration, from food to its individual components, and then down into those component parts (amino acids, simple sugars, fatty acids). And then, showing how they break down and then go into the mitochondria into the citric acid cycle. Stage 1: Digestion 💪 Breaking down food into smaller components (starches and polysaccharides into simple sugars, fats into fatty acids and glycerol, proteins into amino acids) Taking place in the gut lumen (stomach or small intestine) Smaller components (amino acids, simple sugars, disaccharides, monosaccharides) are taken up by the intestine into the blood for further digestion elsewhere Stage 2: Glycolysis 💥 Breaking down a sugar molecule into pyruvate https://www.turbolearn.ai/content/e5ffb167-1f10-4aed-bd7a-9c3f3ede1a75 1/5 9/3/24, 11:27 AM Overview of Cellular Respiration Process First step of harnessing energy from food (in this case, sugar) Glycolysis Equation 1 glucose molecule → 2 pyruvate, 2 ATP, and 2 NADH Steps of Glycolysis Energy investment step (adding ATP to make conditions energetically favorable for glucose breakdown) Cleaving the 6-carbon sugar into 2 3-carbon chains Generating a little energy from each pyruvate 3 irreversible steps: Step 1: Hexokinase or glucokinase adds a phosphate to glucose to make glucose 6 phosphate Step 3: Phosphofructokinase phosphorylates the new hydroxyl group on carbon 1 Step 10: Pyruvate kinase converts phosphoenolpyruvate to pyruvate Other Key Points Fructose 2,6-bisphosphate is an additional way that insulin helps modulate glycolysis Gluconeogenesis: creating sugar from energy sources (typically in the liver) Stage 3: Citric Acid Cycle and Oxidative Phosphorylation 🔋 Breaking down pyruvate to generate more energy Using the end products to generate a gradient within the mitochondria to drive ATP synthesis https://www.turbolearn.ai/content/e5ffb167-1f10-4aed-bd7a-9c3f3ede1a75 2/5 9/3/24, 11:27 AM Overview of Cellular Respiration Process Citric Acid Cycle Overview A ton of steps to take in, but key steps include: Acetyl-CoA formation Citrate formation Isomerization of citrate to isocitrate Oxidation of isocitrate to α-ketoglutarate Oxidation of α-ketoglutarate to succinyl-CoA Oxidative Phosphorylation Using NADH and FADH to pump hydrogen ions across the mitochondrial membrane Creating an H+ gradient that drives ATP synthesis ATP is synthesized from ADP through substrate-level phosphorylation## Electron Transport Chain 🌊 The electron transport chain is a series of enzyme complexes located in the inner mitochondrial membrane. It generates energy for the cell by passing high-energy electrons from NADH and FADH2 to oxygen. Electron Transport Chain Components: Cytochromes (include non-protein parts like iron) NADH dehydrogenase Cytochrome c reductase Cytochrome c oxidase How it Works: Electrons from NADH and FADH2 are passed along the transport chain, releasing energy. https://www.turbolearn.ai/content/e5ffb167-1f10-4aed-bd7a-9c3f3ede1a75 3/5 9/3/24, 11:27 AM Overview of Cellular Respiration Process Energy is used to pump hydrogen ions (H+) into the intermembrane space, creating a gradient. This gradient is used to drive ATP synthesis. Analogy: “You can think of the electron transport chain like a battery or a dam. Energy from NADH and FADH2 is used to "push water up" (pump H+ ions), and then the energy is released when the "dam is uncorked" (H+ ions flow back down).” ATP Generation 📈 2 ATP from glycolysis 34 ATP from the citric acid cycle and oxidative phosphorylation (total: 36 ATP) Note: 32-36 ATP can be generated from 1 glucose, depending on tissue type and shuttles used Mitochondrial Structure 🌿 Outer membrane: double layer of phospholipids Inter membrane space: where H+ ions accumulate Inner membrane: where the electron transport chain and ATP synthase are located Matrix: fluid material where the citric acid cycle and pyruvate to Acetyl- CoA conversion occur Chemoosmosis 🔋 Mechanism of ATP generation that uses energy stored in the form of a proton gradient ATP synthase uses this energy to generate ATP https://www.turbolearn.ai/content/e5ffb167-1f10-4aed-bd7a-9c3f3ede1a75 4/5 9/3/24, 11:27 AM Overview of Cellular Respiration Process Anaerobic Respiration and Fermentation ⚡️ Lactic Acid Fermentation Occurs in the absence of oxygen Pyruvate is converted into lactate, which is secreted from the cell Regenerates NAD+ to maintain glycolysis Alcoholic Fermentation Occurs in yeast, plants, and bacteria Pyruvate is converted into ethanol and CO2 Regenerates NAD+ to maintain glycolysis Fermentation Type Product Organism Lactic Acid Lactate Mammals Alcoholic Ethanol, CO2 Yeast, plants, bacteria Note: Fermentation is necessary to regenerate NAD+ and maintain glycolysis in the absence of oxygen. https://www.turbolearn.ai/content/e5ffb167-1f10-4aed-bd7a-9c3f3ede1a75 5/5