Chapter 5 Microbial Metabolism Microbiology Chapter 5 Microbial Metabolism

What is Metabolism? How an organism uses energy and matter. All of the chemical reactions that take place in organisms. Two Types: Anabolism-to build up. Catabolism-to break down.

Four Basic Types of Metabolic Organisms: Photoautotrophs Photoheterotrophs Chemoautotrophs Chemoheterotrophs

Photoautotrophs Capture light energy to acquire energy through the process of photosynthesis (Carbon dioxide (CO2) in atmosphere). Examples: Plants, phytoplankton,

Photoheterotrophs Depend upon light for their source of energy and mostly organic compounds from other organisms (not CO2) for their source of carbon. Ex. Heliobacteria

Chemoautotrophs Use inorganic energy sources to synthesize organic compounds from carbon dioxide (CO2) Examples: Nitrosomonas, Methanogens

Chemoheterotrophs Use inorganic energy sources to synthesize organic compounds from sources other than CO2 . Their carbon source is derived from other organisms in the forms of sulfur, carbohydrates, lipids and proteins. Examples: Animals, Fungi, Bacterial decomposers

Photosynthesis Photosynthesis is the process used by photoautotrophs to convert energy into matter. 6 H2O + 6 CO2 C6H12O6 + 6 O2 2 Parts: Light dependent and light independent (Calvin cycle) reactions.

Cellular Respiration (Aerobic) Cellular Respiration is the process chemoheterotrophs use to convert organic compounds into energy. 6 O2 + C6H12O6 6H2O + 6 CO2 3 Steps: Glycolysis, Kreb’s cycle and Electron Transport Chain (ETC).

Cellular Respiration (Anaerobic) Anaerobic cellular respiration is the process chemoheterotrophs use when no Oxygen is present. 2 Steps: Glycolysis & Fermentation Two Types of Fermentation: Lactic Acid & Alcoholic Obligate Anaerobes-no Oxygen may be present or they die. Facultative Anaerobes-can survive with or without Oxygen.

Nitrogen Fixation Some Bacteria have the ability to take Nitrogen (N2) out of the atmosphere and into the soil. Symbiotic relationship with a type of plants called legumes (beans)

Nitrification Some soil Bacteria have the ability to break down Nitrogenous waste products (Urea, ammonia).

Denitrification Some Bacteria take the products of Nitrification and convert back into Nitrogen gas in the atmosphere completing the Nitrogen Cycle.