Biochemistry_Complete_Report_Presentation.pptx

A carbs biochemistry presentations

1. Major Metabolic Pathways in Biochemistry Including Glycolysis, Krebs Cycle, and HMP Shunt Prepared by: [Your Name] Date: October 11, 2025

2. Introduction to Metabolism Metabolism refers to the sum of all chemical reactions within living organisms. It consists of two main processes: - Catabolism: Breaking down molecules to produce energy. - Anabolism: Building complex molecules using energy. Three major metabolic pathways are essential for energy production: Glycolysis, Krebs Cycle, and HMP Shunt.

3. Glycolysis Overview Glycolysis occurs in the cytoplasm of cells. It is the breakdown of one molecule of glucose (6C) into two molecules of pyruvate (3C). Does not require oxygen (anaerobic process). Net gain: 2 ATP and 2 NADH. Serves as the first step in both aerobic and anaerobic respiration.

4. Steps of Glycolysis (Phase 1: Energy Investment) 1. Glucose → Glucose-6-Phosphate (via Hexokinase, uses 1 ATP) 2. G6P → Fructose-6-Phosphate 3. F6P → Fructose-1,6-bisphosphate (via Phosphofructokinase, uses 1 ATP) 4. F1,6BP splits into two 3-carbon sugars: G3P and DHAP. 5. DHAP converts into G3P (now 2 G3Ps proceed).

5. Steps of Glycolysis (Phase 2: Energy Payoff) 6. G3P → 1,3-Bisphosphoglycerate (produces 2 NADH) 7. 1,3-BPG → 3-Phosphoglycerate (produces 2 ATP) 8. 3-PG → 2-Phosphoglycerate 9. 2-PG → Phosphoenolpyruvate (PEP) 10. PEP → Pyruvate (via Pyruvate kinase, produces 2 ATP) Total Yield per Glucose: 2 ATP (net) + 2 NADH + 2 Pyruvate.

6. Fate of Pyruvate In aerobic conditions: Pyruvate enters mitochondria and converts to Acetyl-CoA. In anaerobic conditions: Pyruvate converts to lactate (in muscles) or ethanol (in yeast). Acetyl-CoA is the entry molecule for the Krebs Cycle.

7. Krebs Cycle Overview Also called Citric Acid Cycle or TCA Cycle. Occurs in the mitochondrial matrix. Main purpose: Oxidize Acetyl-CoA to CO₂ and produce NADH, FADH₂, and ATP. Each Acetyl-CoA yields: - 3 NADH - 1 FADH₂ - 1 ATP (or GTP) - 2 CO₂

8. Key Steps of the Krebs Cycle 1. Acetyl-CoA + Oxaloacetate → Citrate 2. Citrate → Isocitrate 3. Isocitrate → α-Ketoglutarate (produces NADH + CO₂) 4. α-Ketoglutarate → Succinyl-CoA (produces NADH + CO₂) 5. Succinyl-CoA → Succinate (produces ATP/GTP) 6. Succinate → Fumarate (produces FADH₂) 7. Fumarate → Malate 8. Malate → Oxaloacetate (produces NADH) Cycle repeats for each Acetyl-CoA.

9. Electron Transport Chain (ETC) ETC occurs in the inner mitochondrial membrane. NADH and FADH₂ donate electrons to a series of protein complexes. Energy released pumps protons, creating a proton gradient. ATP Synthase uses this gradient to produce ATP. Final electron acceptor: Oxygen → forms water.

10. HMP Shunt (Pentose Phosphate Pathway) Alternative pathway for glucose metabolism. Occurs in cytoplasm, parallel to glycolysis. Main functions: - Generate NADPH for biosynthetic reactions. - Produce ribose-5-phosphate for nucleotide synthesis. Two phases: Oxidative and Non-oxidative.

11. Phases of HMP Shunt 1. Oxidative Phase: - Produces NADPH and Ribulose-5-phosphate. 2. Non-Oxidative Phase: - Interconverts sugars (Ribulose-5P, Xylulose-5P, G3P, Fructose-6P). NADPH is essential for fatty acid synthesis and protection against oxidative stress.

12. Clinical Importance of Pathways Glycolysis: Essential for energy in red blood cells and hypoxic tissues. Krebs Cycle: Provides intermediates for amino acid and fatty acid synthesis. HMP Shunt: Protects cells from oxidative damage (via NADPH). Defect in G6PD (enzyme of HMP shunt) → Hemolytic anemia due to lack of NADPH.

13. Summary of Energy Yield From one glucose molecule: - Glycolysis: 2 ATP + 2 NADH - Krebs Cycle (per Acetyl-CoA): 3 NADH + 1 FADH₂ + 1 ATP - ETC: Approximately 34 ATP Total: ~36–38 ATP per glucose molecule (aerobic respiration).

14. Conclusion Metabolic pathways are interconnected and essential for sustaining life. Glycolysis provides pyruvate for Krebs Cycle. Krebs Cycle supplies electron carriers for ETC. HMP Shunt provides NADPH and ribose sugars for biosynthesis. Understanding these cycles is crucial in biochemistry and medicine.