Metabolism

Chapter 5

Metabolism

• Metabolism = Anabolism + Catabolism

• Photosynthesis requires Respiration

• Respiration requires Photosynthesis

• Energy Production = Energy Consumption

Chapter 5

Chapter 5

BreakdownProteins to Amino Acids, Starch to Glucose

SynthesisAmino Acids to Proteins, Glucose to Starch

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

• Amino Acids

Chapter 5

Electron Carriers

• Photosynthesis• NADP + H to NADPH

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

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

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

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

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

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

vcell.ndsu.edu/animations/etc/first.htm

• vcell.ndsu.edu/.../atpsynthase_04.htm

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

Fermentation Products

• Alcohol and Carbon Dioxide• Yeast mostly

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

Chapter 5

Fermentation in Yeast

Chapter 5

Fermentation in Muscle

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