Nutrition and Metabolism

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Nutrition and Metabolism

• Metabolism combines
• Anabolism Biosynthesis with
• Catabolism Energy Generation
• Linked by Coupled Reactions

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Metabolic Types

• Energy Generation
• Trapping Light Energy Phototrophs
• Chemical Reactions
• Chemotrophs

• Carbon Source
• CO2 Lithotrophs
• Organic Carbon
• Organotroph
• Chemoorganotrophs are also called Heterotrophs
• Chemolithotrophs

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Bacterial Nutrition

• Macronutrients
• Carbon source
• Nitrogen source
• Phosphate
• Sulfur
• Potassium
• Magnesium
• Calcium

• Sodium
• Iron
• Some bacteria use Siderophores to procure iron
• Micronutrients
• Trace elements
• Growth Factors?

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Culture Media

• Defined media known Composition
• Complex Media Organic mixture
• Agar to Solidify

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Enzymes

• Organic Catalysts
• Proteins
• Reduced Activation Energy
• Speed Reactions
• 108 1020 times

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How Enzymes Act

• Form an Enzyme-Substrate Complex
• Active site of the Enzyme holds
• Substrate

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Enzyme Structure

• Enzymes are Proteins with Active Sites
• Additional Non protein Groups
• Loosely Bound Cofactors - Coenzymes
• Tightly Attached Cofactors- Prosthetic Groups

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Oxidation Reduction

• Redox Reactions
• Oxidation Lose of Electrons
• Reduction Gaining Electrons
• Electron Donors
• Electron Acceptors
• Reduction Potential

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Electron Transfer

• Electron Tower Based on Reduction Potential
• Electron Carrier
• Primary Electron Donor (Food??)
• Energy Source
• Final Electron Acceptor (Waste??)

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Redox Electron Carriers
NAD Nicotinamide Adenine Dinucleotide Freely
diffusible carrier Niacin NADP FMN Flavin
Mononucleotide FAD Riboflavin Quinone
Ubiquinone Vitamin K
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Energy Conservation

• High Energy Compounds (Energy Carriers??)
• ATP Adenosine Triphosphate
• Coenzyme A
• Phosphoenolpyruvate - PEP

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Energy Generation

• Substrate-level Phosphorylation
• Fermentation
• Respiration
• Oxidative Phosphorylation
• Electron Transport (Cascade)

Lactic Acid Fermentation
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Catabolic Pathways

• Glycolysis
• Embden-Meyerhof Pathway
• 3 Stages
• 1. Rearrangement
• 2. Oxidation
• 3. Reduction

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PEP
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Fermentation
Occurs in the absence of O2 Less ATP produced (2
vs 38?) Many fermentation products Substrate acts
as electron donor and acceptor
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Electron Cascade

• Coenzyme
• NADH
• NADH Dehydrogenase
• Flavoproteins
• Quinones
• Cytochromes
• Catalase, Oxidase

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Oxidative Phosphorylation

• Proton Motive Force
• Metabolic Poisons
• Uncouplers
• Dinitrophenol
• Inhibitors
• Carbon
• monoxide
• Cyanide

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Carbon Flow

• Citric Acid Cycle
• Krebs Cycle
• TCA Cycle
• Tricarboxylic Acid Cycle
• Carbon Oxidation
• CO2 Production
• Reduced Coenzymes

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Anaerobic Respiration

• Final Electron Acceptor other than Oxygen

• Nitrate
• Sulfate
• Carbonate
• Iron

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Chemolithotrophy

• Hydrogen Sulfide
• Hydrogen Gas
• Iron
• Ammonia
• Phototrophy
• Catabolism

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Regulation of Enzymes

• Constitutive Enzymes
• not Regulated
• Most Enzymes Can Have Their Activity Regulated
• Feedback Inhibition

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Allosteric Sites
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Isozymes

• Covalent Modification

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Metabolism Word List
Organotroph Lithotroph Chemolithotroph Macronutrie
nts Carbon Nitrogen P, S, K, Mg, Ca, Na, Fe(
siderophores)
Micronutrients Trace Elements Growth
Factors? Culture Media Defined vs. Complex Media
Metabolism Catabolism Anabolism Coupled
Reactions Nutrition Phototroph Chemotroph
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Metabolism Word List 2
Enzymes Organic Catalysts Activation
Energy Enzyme-substrate Complex Active Site
Prosthetic groups Coenzymes Oxidation-Reduction
Redox Reactions Electron Donors Electron
Acceptors
Reduction Potential Electron Tower Electron
Carriers Primary Electron Donor Final Electron
Acceptor
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Metabolism Word List 3
High Energy Compounds Adenosine Triphosphate -
ATP Coenzyme A Fermentation
Substrate-level Phosphorylation Respiration
Oxidative Phosphorylation Electron
Transport Glycolysis
Embden-Meyerhof Pathway Stage I, II,
III Rearrangement Oxidation Reduction
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Metabolism Word List 4
Uncouplers Carbon Flow - Citric Acid Cycle aka
TCA, Tricarboxylic, Krebs Carbon Oxidation CO2
Production
Aerobic Respiration Electron Cascade NADH
dehydrogenase Flavoproteins Quinones
Cytochromes Catalase Oxidase Proton Motive
Force Oxidative Phosphorylation Inhibitors
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Metabolism Word List 5
Reduced Coenzymes Biosynthesis ? Anaerobic
Respiration nitrate, sulfate, carbonate ferric
iron
Chemolithotrophy hydrogen sulfide, hydrogen gas,
ferrous iron, ammonia Phototrophy Catabolism
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