Nutrition and Metabolism Metabolism combines: Anabolism – Biosynthesis with Catabolism – Energy Generation Linked by Coupled Reactions.

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