Metabolism. Chapter 5 Why Study Metabolism? Classification of bacteria –Oxygen Tolerance –Biochemical reactions Acids, Ammonia, Gases Fermentation Products.

Metabolism

Chapter 5

Why Study Metabolism?• Classification of bacteria

– Oxygen Tolerance– Biochemical reactions

• Acids, Ammonia, Gases

• Fermentation Products– Food Products

• Yogurt, Sour Cream, Bread, Alcohol

– Commercial Products• Citric Acid, Plastics

• Environmental Cleanup

Chapter 5

Ying & Yang of Metabolism• Metabolism = Anabolism + Catabolism

• Photosynthesis requires Respiration

• Respiration requires Photosynthesis

• Energy Production = Energy Consumption

Chapter 5

BreakdownProteins to Amino Acids, Starch to Glucose

SynthesisAmino Acids to Proteins, Glucose to Starch

Chapter 5

Chapter 5

Chapter 5

Overview of Metabolism• Source of Energy (Photo- vs.

Chemotroph)– Source of Electrons– Carrier of Electrons– Final Electron Acceptor

• Source of Carbon (Auto- vs. Heterotroph)– Auto- : Carbon Dioxide– Hetero- : Organic Compounds

Chapter 5

Classification based on Metabolism• Where microbes get their energy?

– Sunlight vs. Chemical– Photo- vs. Chemo- trophs

• How do they obtain carbon?– Carbon Dioxide (or inorganic cmpds.) vs.

Organic Compounds (sugars, amino acids)– Auto- vs. Hetero- trophs

• Examples– Photoautotrophs vs. Photoheterotrophs– Chemoautotrophs vs. Chemoheterotrophs

Chapter 5

Chapter 5

Chapter 5

Types of -trophsType Energy C source Example

Photoauto- Sun CO2 Purple &Green sulfurbacteria

Photohetero- Sun OrganicCompounds

Purple &Green Non-sulfur bacteria

Chemoauto- Chemicalbonds

CO2 H, S, Fe, Nbacteria

Chemohetero- Chemicalbonds

OrganicCompounds

Most bacteria,fungi,protozoa,animals

Chapter 5

Source of Electrons• Autotrophs

– Photosynthesis

– H2O, H2S

• Chemotrophs– Organic Compounds

– Carbohydrates (C H2O)• Glucose, Lactose, Sucrose, Mannitol, Citrate

– Amino Acids

Chapter 5

Electron Carriers• Photosynthesis

– NADP + H to NADPH

• Respiration– NAD + H to NADH– FAD + H to FADH

• Contain Niacin and Riboflavin– Vitamins, not stable– Can’t store these molecules

Chapter 5

Final Electron Acceptor• Photosynthesis

– CO2 + H’s to CH2O

– Stores energy

• Respiration– Aerobic

• 1/2 O2 + H 2 to H2O

– Anaerobic• Fermentation

Chapter 5

Movement of Electrons• Chemical reactions

• Oxidation Reactions

• Reduction Reactions

• Reactions Coupled– Redox reactions

Chapter 5

Chapter 5

Example of Redox Equations

Chapter 5

Example of Redox Equations

Chapter 5

Example of Redox Equations

Chapter 5

Examples• ATP ADP + P

– Oxidation, release energy

• ADP + P ATP– Reduction, stores energy

• NAD + H NADH

• FADH FAD + H

• NH4 + 11/2O2 NO2

- +H2O + 2H + ATP

• 2H2 + O2 2H2 O

Chapter 5

Examples• Cellular Respiration

– C6H12 O6 + 6O2 6H2O + 6CO2 + 38 ATP

• Photosynthesis– 6H2O + 6CO2 + light C6H12 O6 + 6O2

• Nitrification– NH4 NO2 to NO3

• Ammonia to Nitrite to Nitrate

• Ammonification– N2 NH4

Chapter 5

Respiration• Overview;

– Glucose to Carbon dioxide + Water +Energy

– C6H12O6 + O2 6CO2 + 6H2O + 38 ATP

– Glucose is highly reduced; contains energy– Oxygen receives the electrons to form

energy

• 4 separate reactions– Glycolysis, Transition Reaction, Krebs

Cycle, Electron Transport, Chemiosomosis

• Requires Oxygen

Chapter 5

Steps in Respiration• Electron Donors

– Organic Compounds (Glucose preferred)

• Electron Carriers– NAD to NADH– FAD to FADH

• Electron Acceptors-Terminal– O2 to H2O

• Phosphorylation Reactions– ADP to ATP

• Chemiosmosis Reactions

Chapter 5

Glycolysis- 10 steps• Glucose is Phosphorylated to form

Fructose 1,6-diphosphate

• Split to form 2 Glyceraldehyde 3-phosphate

• Final Products are:– 2 Pyruvic Acid (C3H4O3)

• Compare to original glucose - C6H12O6

– 2 NADH– 2 ATP

Chapter 5

Chapter 5

Transition Reaction• Pyruvic Acid Acetyl - Co A + CO2 +

NADH

• C2H4O2

Chapter 5

Kreb’s Cycle• Figure E.3, A29

• Acetyl CoA Carbon Dioxide– C2H4O2 to CO2

– Energy produced/Acetyl CoA (x2 for /Glucose)

• 3 NADH• 1 FADH• 1 ATP

• Metabolic Wheel– Fats, amino acids, etc. enter or leave– Citrate is product of first reaction

• Simmons Citrate Media

Chapter 5

Electron Transport Chain• NADH oxidized to NAD

• FAD reduced to FADH

• Cytochromes shuffle electrons finally to O2

– Cytochrome Oxidase important in G - ID

• H2O formed and ATP

• 3 ATP / 1 NADH

• 2 ATP / 1 FADH

Chapter 5

Chapter 5

Chapter 5

Chapter 5

Chapter 5

Fermentation Products from Pyruvate

• Homolactic = Lactic Acid– Yogurt, Lactobacillus

• Alcohol + CO2

• Propionic Acid

• Butyric Acid

• Acetic Acid

• Succinic Acid

• Butylene to Acetoin– basis for VP Test (Vogues-Proskauer)

Chapter 5

Fermentation Products• Alcohol and Carbon Dioxide

– Yeast mostly

• Lactic Acid– Humans, muscles without oxygen– Bacteria (Lactobacillus-yogurt)

• Butyric Acid– Rancid butter, Clostridium-gangrene

• Acetoin – Butanediol fermentation in Klebsiella

• Propionic Acid – Swiss Cheese

Chapter 5

Fermentation in Yeast

Chapter 5

Fermentation in Muscle

Chapter 5

Chapter 5

Chapter 5

Photosynthesis

• Plants– CO2 + H2O + Light C6H12O6 + O2

– Water is split to release electrons

• Bacteria– H2S is used not water

• Sulfur or Sulfuric Acid formed• Oxygen not released

– Chlorophyll is different– Strict Anaerobe– Purple & Green Sulfur Bacteria

Chapter 5

Chemiosmosis• Production of ATP in Electron Transport

• Electrochemical Gradient Formed between membranes

• H+ (Protons) generated from NADH

• Electrical Force (+) & pH Force (Acid)

• Gradient formed

• ATPase enzyme that channels H+ from High to Low concentration– 3 ATP/NADH– 2 ATP/NADH

Chapter 5

Chapter 5

Summary of Respiration• Aerobic Respiration

– Glycolysis– Transition Rx.– Kreb’s Cycle– Electron Transport

Chain

• Anaerobic Respiration– Pyruvate

• Lactic Acid• Mixed Acids• Alcohol + CO2

– Recycle NADH– 2 ATP / Glucose