Metabolism Study Guide PDF

Metabolism 1. Define metabolism and the difference between anabolism and catabolism. Metabolism is the total of all chemical reactions happening in your body to keep you alive. It’s like the body's engine. Anabolism is building things up (like muscle growth), and it requires energ...

Metabolism 1. Define metabolism and the difference between anabolism and catabolism. Metabolism is the total of all chemical reactions happening in your body to keep you alive. It’s like the body's engine. Anabolism is building things up (like muscle growth), and it requires energy. Think of it like constructing a building. Catabolism is breaking things down (like digesting food), and it releases energy. It’s like tearing down a building for parts. 2. Three ways ATP is generated: Substrate-level phosphorylation: This happens during reactions like glycolysis, where a phosphate group is directly added to ADP to make ATP. Think of it like manually attaching a battery to a machine to power it. Oxidative phosphorylation: This uses energy released from electrons moving through the electron transport chain (ETC). It’s like charging a battery with a power plant. Photophosphorylation: This happens during photosynthesis in plants when light energy is used to create ATP. Think of it like solar power charging a battery. 3. Examples of three phosphorylation reactions that generate ATP: Glycolysis: Breaks down glucose and makes some ATP through substrate-level phosphorylation. Electron Transport Chain (ETC): The final step in respiration that generates a lot of ATP using oxidative phosphorylation. Photosynthesis: In plants, light energy powers the generation of ATP in chloroplasts. 4. The overall function of metabolic pathways: Metabolic pathways help break down food into energy or build up molecules the body needs. They are like assembly lines in a factory, where each step has a role in producing energy or materials. 5. How is ATP intermediate between catabolism and anabolism? Catabolism breaks down molecules to release energy, which is stored in ATP. Anabolism then uses this ATP energy to build things (like muscles or proteins). ATP acts as the currency or middleman between the two processes. 6. What is the purpose of a metabolic pathway? A metabolic pathway is like a series of steps that convert one thing into another (for example, glucose to energy). Each step ensures the process is efficient and produces the necessary outcomes (like ATP or building blocks for cells). 7. Why is glucose so important for organisms? Glucose is the main energy source for cells. It’s broken down during cellular respiration to produce ATP, which powers everything in your body—from thinking to moving your muscles. Aerobic and Anaerobic Respiration; Fermentation 1. Aerobic respiration: This is how your body uses oxygen to turn glucose into energy (ATP). It’s the most efficient way to produce energy, releasing carbon dioxide, and water as waste. The reaction is: Glucose + Oxygen → Carbon Dioxide + Water + ATP (Energy) 2. Glycolysis: The first step is breaking down glucose. It happens in the cytoplasm of the cell and doesn’t need oxygen. It splits glucose into two molecules of pyruvate, producing a small amount of ATP. 3. Preparatory reaction for the citric acid cycle: Pyruvate is turned into acetyl-CoA, which is needed for the Krebs cycle. It’s like preparing food for the oven—getting the materials ready for the next big step.  4. Products of the Krebs cycle: The Krebs cycle (or citric acid cycle) produces: ATP (a small amount), NADH and FADH₂ (electron carriers for the next stage), CO₂ (waste gas). It’s like filling up energy tanks (NADH and FADH₂) that will be used later. 5. What happens in the electron transport chain? Electrons from NADH and FADH₂ travel through the electron transport chain in the mitochondria, releasing energy to pump protons and produce ATP. It’s the main stage where the majority of ATP is produced (think of it as the final big push to generate energy). 6. How do carrier molecules function in the electron transport chain? NADH and FADH₂ act like delivery trucks, bringing high-energy electrons to the chain. As these electrons move through, they help generate a lot of ATP. 7. Compare aerobic and anaerobic respiration: Aerobic uses oxygen and produces more ATP (36-38 per glucose). Anaerobic doesn’t use oxygen and produces less ATP (only 2 per glucose). 8. Fermentation chemical reactions and products: When there’s no oxygen, cells use fermentation to produce energy. This process generates lactic acid (in muscles) or alcohol (in yeast). It’s less efficient than aerobic respiration. 9. Four compounds made from pyruvic acid during fermentation: Lactic acid, ethanol, carbon dioxide, and acetone are common products made from pyruvic acid when oxygen isn’t available. 10. Compare energy yield of aerobic respiration, anaerobic respiration, and fermentation: Aerobic: Produces the most ATP (36-38 per glucose). Anaerobic: Only 2 ATP per glucose. Fermentation: Also 2 ATP, like anaerobic respiration. 11. End-products of lipid and protein catabolism and where they enter respiration: Lipids are broken into fatty acids and glycerol; fatty acids enter respiration as acetyl-CoA. Proteins break down into amino acids; they enter at various points such as pyruvate or the Krebs cycle. 12. Common reaction step in all three ATP-generating methods: Glycolysis is the first step for aerobic, anaerobic respiration, and fermentation, where glucose is broken down into pyruvate and a little ATP is produced.