This preview shows pages 1–3. Sign up to view the full content.
This preview has intentionally blurred sections. Sign up to view the full version.View Full Document
Unformatted text preview: Biochem II Notes PART 3 I. TCA Cycle (aka Krebs cycle, Citric Acid Cycle) A. Basic Review 1. Cellular Respiration a. Physiological Respiration = Inhale O 2 , exhale CO 2 b. Cellular Respiration = Cells consume O 2 to produce ATP and CO 2 2. 3 Stages of Catabolism a. Stage 1 = Glycolysis and Oxidative Decarboxylation (Glucose to Pyruvate to Acetyl CoA) b. Stage 2 = Oxidation of AcCoA by the TCA cycle (burn glucose to get NADH and FADH 2 . c. Stage 3 = Electron Transfer & Oxidative Phosphorylation to get LOTS of ATP. Oxidative Phosphorylation is when inorganic phosphate is added to ADP to make ATP. The energy required comes from electrons and OXYGEN IS NEEDED! d. Substrate Level Phosphorylation 3. Key Points a. Glycolysis 1) Happens IN THE CYTOPLASM 2) ANAEROBIC (Does not require oxygen) b. Oxidative Decarboxylation & TCA 1) Oxidative Decarboxylation of Pyruvate to get ATP = Oxidizing/burning a Carbon to get ATP 2) Both Happen IN THE MITOCHONDRION Matrix 3) Both are AEROBIC (Need Oxygen – Sort of) 4) TCA cycle is coupled to Electron Transport Chain and Oxidative Phosphorylation. If one of the three stops, they all grind to a halt! The only process that uses oxygen is Ox Phos – however, because they are coupled, we call all 3 aerobic. Without Oxygen, OxPhos stops, causing ETC and TCA to also come to a halt. c. Oxidative Phosphorylation 1) Happens ON the INNER MEMBRANE of the MITOCHONDRIA 2) Also AEROBIC (Needs Oxygen) This is the part that requires Oxygen! 4. Aerobic Energy Metabolism a. Called “Cellular Respiration” b. TCA Cycle is the final COMMON PATHWAY for Oxidation of fuel c. Acetyl CoA comes from; Pyruvate (from CHOs), Fatty Acids, Amino Acids (from Proteins) d. Acetyl CoA enters the TCA cycle. 2 more CO 2 are released e. They enter the Electron Transport chain and oxidative phosphorylation B. Overview of the TCA Cycle 1. Before and After the TCA cycle a. Before: Glycolysis & Oxidative Decarboxylation of Pyruvate to Acetyl CoA. Pyruvate... 1) Comes From; Glycolysis, Lactate, OAA, Alanine (protein) 2) Fates of Pyruvate = Gluconeogenesis, Lactate, Alanine (protein), OAA, Acetyle CoA. Note; Acetyly CoA cannot go back to pyruvate! b. After: Oxidative Phosphorylation to make ATP (OxPhos) c. ATP Production (Net in liver) is 38 ATP per molecule of Glucose 2. Muscle & Brain vs. Liver a. Muscle & Brain: Need lots of energy, so they take TCA to make ATP b. Liver: A low energy organ. TCA shuffles carbon skeletons to amino acids & lipid (fat). Glucose to Fat? 3. TCA Cycle Synonyms a. Tri-carboxylic acid cycle (Citric Acid has 3 –COOH’s) b. Citric Acid Cycle: 1 st step of cycle takes OAA + Acetyl CoA = Citric Acid (remember Citric acid vs. Citrate?) c. Krebs cycle; After Sir Hans Krebs 4. Energy a. TCA cycle is a hub in metabolism b. Catabolic Pathways = IN = oxidize glucose to ATP c. Anabolic Pathways = OUT = produces biosynthetic precursors d. Amphibolic = both Catabolic and Anabolic in same pathway e. Closely regulated in relation to other pathways...
View Full Document
This note was uploaded on 11/21/2011 for the course CHEM 1516 taught by Professor Bertsilverman during the Fall '10 term at Life Chiropractic College West.
- Fall '10