BIOD 171/ BIOD 171 Module 2 Metabolism & Photosynthesis Review (Latest 2026/2027 Update) | Complete Q&A with Verified Answers and Detailed Rationales | Essential Microbiology with Lab | A+ Graded | Portage

INSTANT PDF DOWNLOAD – This is the comprehensive Module 2 Metabolism & Photosynthesis Review for BIOD 171 Essential Microbiology with Lab at Portage Learning (Latest 2026/2027 Update), featuring 100+ verified exam questions with correct answers and detailed rationales . This review covers all key topics including metabolism (catabolism vs anabolism, enzyme function, cofactors, ATP/ADP energy transfer), cellular respiration (glycolysis, TCA cycle, electron transport chain, fermentation), and photosynthesis (light reactions, Calvin cycle, photophosphorylation) . Key Topics & Practice Q&A Metabolism Fundamentals Q: What is the difference between catabolism and anabolism? Answer: Catabolism is the breakdown of molecules to release energy; anabolism is the synthesis of molecules that requires energy. Rationale: Metabolism is the sum of all chemical reactions in a cell. Catabolic reactions break down complex molecules into simpler ones, releasing energy. Anabolic reactions use that energy to build complex molecules from simpler ones. Q: How do enzymes work? Answer: Enzymes lower the activation energy required for a chemical reaction, speeding up the rate of the reaction without being consumed. Rationale: Enzymes are biological catalysts. They bind to substrates at their active sites, facilitating the conversion of substrates into products. Cofactors are non-protein molecules that assist enzyme function. Q: What is the role of ATP in metabolism? Answer: ATP (adenosine triphosphate) is the primary energy currency of the cell, transferring energy from catabolic reactions to anabolic reactions. Rationale: ATP stores energy in its high-energy phosphate bonds. When ATP is hydrolyzed to ADP (adenosine diphosphate), energy is released to drive cellular work. Cellular Respiration Q: What is glycolysis and where does it occur? Answer: Glycolysis is the breakdown of glucose into two pyruvate molecules, producing a net yield of 2 ATP and 2 NADH. It occurs in the cytoplasm . Rationale: Glycolysis is the first step in cellular respiration and does not require oxygen. It splits a 6-carbon glucose molecule into two 3-carbon pyruvate molecules. Q: What are the products of the TCA cycle (Krebs cycle)? Answer: The TCA cycle produces NADH, FADH₂, ATP (or GTP), and CO₂. Rationale: The TCA cycle is a series of chemical reactions that oxidize acetyl-CoA to carbon dioxide and generate reduced electron carriers (NADH and FADH₂) and a small amount of ATP. Q: Where does the electron transport chain (ETC) occur and what is its function? Answer: The electron transport chain occurs in the inner mitochondrial membrane (in eukaryotes) or the cytoplasmic membrane (in prokaryotes). It generates a proton gradient that drives ATP synthesis via oxidative phosphorylation. Rationale: The ETC uses NADH and FADH₂ to power the pumping of protons across the membrane. The flow of protons back across the membrane through ATP synthase produces the majority of ATP in aerobic respiration. Fermentation Q: What is the purpose of fermentation? Answer: Fermentation regenerates NAD⁺ from NADH, allowing glycolysis to continue and produce ATP in the absence of oxygen. Rationale: In the absence of oxygen, the electron transport chain cannot function. Fermentation provides an alternative pathway to recycle NAD⁺ so that glycolysis can continue, producing a net yield of 2 ATP per glucose. Photosynthesis Q: What are the light reactions of photosynthesis? Answer: The light reactions capture light energy and use it to produce ATP and NADPH. Rationale: Light reactions occur in the thylakoid membranes of chloroplasts. Light energy is absorbed by chlorophyll and used to generate ATP through photophosphorylation and reduce NADP⁺ to NADPH. Q: What is the Calvin cycle? Answer: The Calvin cycle uses ATP and NADPH to fix CO₂ into glucose. Rationale: The Calvin cycle is a series of enzyme-catalyzed reactions that occur in the stroma of chloroplasts. It uses the energy from ATP and the reducing power of NADPH to convert CO₂ into organic molecules. It requires 6 turns to produce one glucose molecule .