•Amino AcidsSide chain properties: hydrophobic/hydrophilic, pKa, functionalgroups•Enzyme kinetics and thermodynamicsTransition state stabilization, allostery•Organic chemistryLewis acidity/basicity, nucleophiles and electrophiles, electronsand curly arrows•Carbohydrate chemistrySimple sugars: nomenclature and structure•Cell biologyThe structure of cells, organelles, membranesMetabolismWhat Do You Need To Know?1The Component Parts of Complex OrganismsPerform Different Functions and have DifferentRequirements2Functional Compartmentalization is Even MoreApparent at the Cellular Level3Overview of Metabolismlactatepyruvateacetyl-CoANAD+NADHADPATPIIIIIIIVNADHanaerobicTCACYCLEGLUCONEOGENESISliver and kidneysGLYCOLYSIScytoplasm, all cellsamino acidsfatsOXIDATIVE PHOSPHORYLATIONmitochondria, all cellsCO2glucoseNAD+mitochondrial membraneglycogenH+H+Enzyme or enzyme complex. Mayparticipate in more than one pathwayO2aerobic4Metabolism• The sum of the chemical changes that convert nutrients into energyand the chemically complex products of cells• Hundreds of enzyme reactions organized into discrete pathways• Substrates are transformed to products via many specificintermediatesA Common Set of Pathways• Organisms show marked similarities in their major metabolicpathways• Evidence that all life descended from a common ancestral form• But there is significant diversity– Autotrophs use CO2– Phototrophs use light– Heterotrophs use organic carbon– Chemotrophs use sugars, inorganics and sulfur• Phototrophs use light to drive synthesis of organic molecules• Heterotrophs use these organic molecules as building blocks• CO2, O2, and H2O are recycledThe Sun is Energy for Life5Metabolism• Catabolism: degradative pathways– usually energy-yielding!• Anabolism: biosynthetic pathways– energy-requiring!• Catabolic pathways converge to a few end products• Anabolic pathways diverge to synthesize many biomolecules• Some pathways serve both in catabolism and anabolism• Such pathways are said to be amphibolic6Metabolic Pathways• Pathways consist of sequential steps• The enzymes may be separate• Or may form a multienzyme complex• Or may be a membrane-bound system• New research indicates that multienzyme complexes are morecommon than once thought73 Stages of Catabolism8metabolic regulation favors different pathways for oppositely directedmetabolic sequences• Anabolic & catabolic pathways involving the same product are not thesame although some steps may be common to both• Some steps must be different to ensure that each pathway isspontaneous• This also allows regulation mechanisms to turn one pathway on andthe other offMetabolic RegulationRedox in Metabolism• Catabolism is oxidative - substrates lose reducing equivalents, usuallyH- (hydride) ions• NAD+ collects electrons released in catabolism and is reduced to NADH• Anabolism is reductive - NADPH provides the reducing power(electrons) for anabolic processes9NADH and NAD+, NADPH and NADP+• H- transferred to the pyrimidine nucleotide NAD+• Dehydrogenase reactions AH2 + NAD+ A + NADH + H+• eg alcohol dehydrogenaseNADPH Provides the Reducing Power for AnabolismNAD+ is an Anabolic Oxidizing