metabolism 1 ppt

7/29/2019 Metabolism 1 Ppt

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Microbiology

MicrobialMetabolismIIntroductiontoMetabolism

Ching-TsanHuang()

Office: Room 111, Agronomy HallTel: (02) 33664454

E-mail: [email protected]


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IntroductionWhystudymicrobiology?

To control and utilization of MICR RGANI$M$

Transport

ChemicalWork

Mechanical

Heat

Metabolism

Catabolism

Anabolism

Physiology

Photosynthesis

Maintenance

Growth

Respiration

Reproduction

Fermentation

Physiology: The study of life processes in living cells

Metabolism: The total of all chemical reactions in cells

Whymicrobialmetabolism?

LightEnergy


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Substrates ProductsAnabolism

Enzymes

Overviewofmetabolism

LightEnergy

Photosynthesis

Energy

Catabolism

Purpose: Trapping, generation and use of energy

Where: within cells (under controlled temperature and pH)

How: catalyzed by enzymes


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Metabolismofmicroorganisms

Interchangeable

Macro-tomicro-moleculesorviceversa

Catabolism

Polysaccharides

Lipids

Proteins

Nucleicacids

Polymers

Monosaccharides

Fattyacids,glycerol

Aminoacids

Nucleotides

Monomers

Anabolism

CO2

H2O,O2

NH4+,NO3-

PO4-,SO4=

Molecules


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Oxidation-ReductionReaction

ElectronCarriers

ATP (adenosine triphosphate)

ReactionandEnergy

Without

enzyme

With

enzyme


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Oxidation-ReductionReaction


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ElectronTransportSystems

NADH


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ElectronCarriersTransferelectronsbetweendifferentlocations

Energyflowinmetabolism

NAD+ nicotinamide adenine dinucleotide

NADP+ nicotinamide adenine dinucleotide phosphate


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ATP:AdenosineTriPhosphate

Ahigh-energymolecule

ATP + H2O ADP + Pi Go = -7.3 kcal/mol


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EnzymeStructure

Apoenzyme

protein component of an enzyme

Cofactor

nonprotein component of an enzymeprostheticgroup firmly attached

coenzyme loosely attached

Holoenzyme = apoenzyme + cofactor

Coenzymeoften act as carriers, transporting

substances around the cell


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Enzymes:Classification

Oxidoreductase

Transferase

Hydrolase

Lyase

Isomerase

Ligase


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Enzymes

CharacteristicsLower activation energy

Key-Lock relation:

active or catalytic site

Catalyze reactions by

concentrating substrateand binding correctly

Environmental

Effects

pHTemperature

Denature


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MetabolicRegulation

NatureExceptionally complex and difficult

Able to respond to environmental changes

Significance

Essential for the cell to conserve energy and materialEssential for the cell to maintain metabolicbalance

How

Amount of metabolites and enzymes

Activity of enzymesFeedback inhibition


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MetabolicChanneling

Compartmentationthe differential distribution of enzymes and

cofactors among separate cell structures

Enzymeactivityis coordinated

through regulation of

the transport of

metabolites and

coenzymes betweencell compartments


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RegulationMechanisms

CentralDogma


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AllostericRegulation


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Example

E.coliACTase


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CovalentModification

Reversibleaddition

orremovalofa

chemicalgroup

altersenzymeactivity


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Feedback(EndProduct)InhibitionMaintainappropriateconcentrationforeachmetabolite

Pacemakerenzymeorrate-determiningreaction

metabolism 1 ppt

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