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Nutrition and Metabolism
• Metabolism combines:• Anabolism –
Biosynthesis with• Catabolism – Energy
Generation• Linked by Coupled
Reactions
Metabolic Types
• Energy Generation:• Trapping Light Energy
Phototrophs• Chemical Reactions
Chemotrophs
Carbon Source:
CO2 –Lithotrophs
Organic Carbon –
Organotroph
Chemoorganotrophs are also called Heterotrophs
Chemolithotrophs
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?
Culture Media
• Defined media – known Composition
• Complex Media – Organic mixture
• Agar to Solidify
Enzymes
• Organic Catalysts• Proteins• Reduced Activation
Energy• Speed Reactions• 108 – 1020 times
How Enzymes Act
• Form an Enzyme-Substrate Complex
• Active site of the Enzyme holds
Substrate
Enzyme Structure• Enzymes are Proteins with Active Sites• Additional Non protein Groups• Loosely Bound Cofactors - Coenzymes• Tightly Attached Cofactors- Prosthetic Groups
Oxidation – Reduction
• Redox Reactions
• Oxidation – Lose of Electrons
• Reduction – Gaining Electrons
• Electron Donors
• Electron Acceptors
• Reduction Potential
Electron Transfer
• Electron Tower Based on Reduction Potential
• Electron Carrier
• Primary Electron Donor (Food??)– Energy Source
• Final Electron Acceptor (Waste??)
Redox Electron Carriers
NAD –Nicotinamide Adenine DinucleotideFreely diffusible carrierNiacinNADP
FMN – Flavin MononucleotideFADRiboflavin
Quinone –UbiquinoneVitamin K
04/19/23
Energy Conservation
• “High” Energy Compounds (Energy Carriers??)
• ATP – Adenosine Triphosphate
• Coenzyme A
• Phosphoenolpyruvate - PEP
Energy Generation
• Substrate-level Phosphorylation
• Fermentation• Respiration• Oxidative
Phosphorylation– Electron Transport
(Cascade)Lactic Acid Fermentation
Catabolic Pathways
• Glycolysis
• Embden-Meyerhof Pathway
• 3 Stages
1. Rearrangement
2. Oxidation
3. Reduction
PEP
Fermentation
Occurs in the absence of O2
Less ATP produced (2 vs 38?)
Many fermentation products
Substrate acts as electron donor and acceptor
Electron Cascade
• Coenzyme • NADH• NADH
Dehydrogenase• Flavoproteins• Quinones• Cytochromes• Catalase, Oxidase
Oxidative Phosphorylation
Proton Motive Force• Metabolic Poisons• Uncouplers
Dinitrophenol• Inhibitors
Carbon
monoxide
Cyanide
Carbon Flow
• Citric Acid Cycle• Krebs Cycle• TCA Cycle• Tricarboxylic Acid
Cycle• Carbon Oxidation
• CO2 Production
• Reduced Coenzymes
Anaerobic Respiration
• Nitrate• Sulfate• Carbonate• Iron
• Final Electron Acceptor other than Oxygen
Chemolithotrophy
• Hydrogen Sulfide• Hydrogen Gas• Iron• Ammonia
• Phototrophy• Catabolism
Regulation of Enzymes
• Constitutive Enzymes
not Regulated• Most Enzymes Can
Have Their Activity Regulated
• Feedback Inhibition
Allosteric Sites
Isozymes
• Covalent Modification
Metabolism Word List
Metabolism
Catabolism
Anabolism
Coupled Reactions
Nutrition
Phototroph
Chemotroph
Organotroph
Lithotroph
Chemolithotroph
Macronutrients
Carbon
Nitrogen
P, S, K, Mg, Ca, Na, &
Fe( siderophores)
Micronutrients
Trace Elements
Growth Factors?
Culture Media
Defined vs. Complex Media
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
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
Metabolism Word List 4
Aerobic Respiration
Electron Cascade
NADH dehydrogenase
Flavoproteins
Quinones
Cytochromes
Catalase
Oxidase
Proton Motive Force
Oxidative Phosphorylation
Inhibitors
Uncouplers
Carbon Flow - Citric Acid Cycle
aka TCA, Tricarboxylic, Krebs
Carbon Oxidation
CO2 Production
Metabolism Word List 5
Reduced Coenzymes
Biosynthesis ?
Anaerobic Respiration
nitrate, sulfate, carbonate
ferric iron
Chemolithotrophy
hydrogen sulfide, hydrogen gas, ferrous iron, ammonia
Phototrophy
Catabolism