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EVY YULIANTI evy_yulianti@uny.ac.id. Getting Energy From Food. Not responsible for: Enzyme names and molecular structures, (unless discussed specifically in class Details of metabolic pathways. What are the major pathways of metabolism of our principal energy sources? Carbohydrates Fats
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EVY YULIANTI evy_yulianti@uny.ac.id
Getting Energy From Food Not responsible for: Enzyme names and molecular structures, (unless discussed specifically in class Details of metabolic pathways Getting Energy From Food
What are the major pathways of metabolism of our principal energy sources? Carbohydrates Fats Protein What are the end-products? What are the waste products? Getting Energy From Food
How is energy transferred to ATP? Substrate-level phosphorylation Chemiosmotic phosphorylation How is energy of ATP used? -- energetically unfavorable Rxs Figure 3-33 Getting Energy From Food
What are Functions of NAD, NADP, FAD? Electron carriers Oxidation / reduction reactions NAD and catabolic reactions -- substrate oxidation -- H- used for ATP synthesis NADP and anabolic reactions -- substrate reduction -- e.g., --COOH to C=O to C-OH Getting Energy From Food
Overview of Carbohydrate Catabolism • You are expected to be familiar with the: • functions and metabolic relationships between: • Glycolysis • Fermentation • Transition reaction • Krebs (TCA) cycle • Electron transport • and their cellular locations • roles/requirements for O2 and CO2 in these processes Getting Energy From Food
Overview of Glycolysis Substrate-level phosphorylation vs Chemiosmotic phosphoryltion Getting Energy From Food
How does fermentation allow cells to produce ATP in the absence of oxygen? -- detoxifying of pyruvate -- regeneration of NAD How long can this go on…? What happens to the lactate? Cori-cycle (a little physiology) Lactic Acidosis Getting Energy From Food
Oxidation of Pyruvate to Acetyl-CoA The Pyruvate Dehydrogenase Complex -- huge -- highly regulated Activators: ADP, NAD, CoA Inhibitors: ATP, NADH, acCoA Getting Energy From Food
How are triglycerides oxidized? Fatty acids and glycerol Beta-oxidation 1 FADH & 1 NADH / acCoA How many FADH and NADH would be produced from a 16 carbon FA? Getting Energy From Food
Krebs Cycle Getting Energy From Food
Using NADH to make ATP Electron transport and oxidative phosphorylation You should be able to complete a table to calculate energy yields from glucose or fatty acids (of any given length) -- assuming 2.5 ATP per NADH (1.5 per glycolytic NADH) and 1.5 ATP per FADH • From glucose • GlycolysisATP yield • ____ NADH x ____ ATP _______ • ____ ATP _______ • Transition Rx • ____ NADH x ____ ATP x 2 pyr _______ • Krebs cycle • ____ NADH x ____ ATP x 2 pyr _______ • ____ FADH x ____ ATP x 2 pyr _______ • ____ GTP x ____ ATP x 2 pyr _______ • Total 30 • From a 12 carbon fatty acid • B-oxidationATP yield • ____ FADH x ____ ATP x 6 acCoA _______ • ____ NADH x ____ ATP x 6 acCoA _______ • Krebs cycle • ____ NADH x ____ ATP x 6 acCoA _______ • ____ FADH x ____ ATP x 6 acCoA _______ • ____ GTP x ____ ATP x 6 acCoA _______ • Total 84 Getting Energy From Food
What are the biosynthetic roles Of these pathways? Getting Energy From Food
Integrated Metabolism (Note Metabolic Linkage by G6-P, Pyruvic Acid and Acetyl CoA)
Dominant Absorptive Reactions: Most cells oxidize glucose to ATP, CO2 and H2O