BIOLCHEM 415 1st Edition Lecture 13Outline of Last Lecture I. Monosaccharides are the simplest carbohydratesII. Carbohydrates can attach to proteins forming glycoproteinsIII. Digestion cleaves large molecules for use in metabolismOutline of Current Lecture IV. Metabolism is composed on many interconnected reactionsV. ATP is the universal cellular currency of free energyVI. Oxidation of Carbon fuel is important to cellular energyVII. Metabolic pathways contain many recurring motifsVIII. Regulation of Metabolic pathwaysCurrent LectureIntermediary metabolism- Catabolism - fuel cellular energy- Anabolism- consume energy and produce macromolecules- Amphibolic pathway- pathway can be either catabolic or anabolic depending on cell demands- all pathways are regulated individually- each non-reversible path is very distinctEnergy is required for life- phototrophs – create energy using light- chemotrophs – create energy through oxidation of carbon fuels (us)These notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.Basic Principles1) energy substrates are degraded and complex molecules are synthesized (stepwise reactions)2) ATP is the general energy currency3) ATP is formed by the oxidation of carbon fuels4) a number of reaction types exist that are common to all metabolic pathways5) metabolic pathways are highly regulatedFor metabolic pathways to occur:1) the individual reaction must be specific2) it must be thermodynamically favorable (G < 0)- thermodynamics are discussed in lecture 6Coupled reactions drive pathways- coupling a reaction can make it more thermodynamically favorableATP: universal energy source- structural basis for high energy- charge repulsion- resonance stabilization- stabilization by hydration- thermodynamically stable but kinetically unstable- exercise requires continuous availability - each ATP ADP conversion causes short burst of energyOther high energy phosphates- phosphoryl-transfer provides the energy transformationCarbon fuels- created through oxidation reactions- the more reduced a carbon atom the more free energy released- oxidation yields CO2- fats are a better fuel source than carbohydrates for this reason- one carbon atom is oxidized at a timeTwo ways to generate ATP: phosphorylation and oxidation- substrate-level phosphorylation- direct transfer of phosphoryl group from higher phosphorylated compound to ADPActivated carriers (recurring motifs)- carry activated electrons derived from the oxidation of fuels- ATP phosphoryl carrier- NAD+ NADH- NADPH provides electrons for synthesis- as well as FAD and FMNRegulation of Metabolism1) Control amount of enzymes2) Control enzyme’s catalytic activities- can be exerted by small activators or inhibitors or by covalent modification3) Control of accessibility of substratesHallervorden-Spatz Syndrome- pantothenate kinase associated degeneration- regulatory enzyme- deficiency causes neurodengeneration and iron
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