Microbial Physiology and Genetics

• Physiology 


  the study of the vital life processes of organisms
• Microbial physiology 


  concerns the vital life processes of microorganisms
• Bacteria, fungi, and viruses


  used extensively in genetic studies because they produce generation after generation so rapidly
• carbon, hydrogen, oxygen, nitrogen, phosphorus, and sulfur.

  six major chemical elements
• carbohydrates, lipids, proteins, and nucleic acids

  macromolecules of life
• essential nutrients


  Materials that organisms are unable to synthesize, but are required for building macromolecules and sustaining life
• Phototrophs 


  use light as an energy source
• Chemotrophs 


  use either inorganic or organic chemicals as an energy source
• Chemolithotrophs


  use inorganic chemicals as an energy source
• Chemoorganotrophs 


  use organic chemicals as an energy source
• Autotrophs 


  use carbon dioxide as their sole source of carbon
• Heterotrophs


  use organic compounds other than CO2 as carbon sources.
• Photoautotrophs 


  use light as an energy source and CO2 as a carbon source
• Photoheterotrophs


  use light as an energy source and organic compounds other than CO2 as a carbon source
• Chemoautotrophs 


  use chemicals as an energy source and CO2 as a carbon source.
• Chemoheterotrophs


  use chemicals as an energy source and organic compounds other than CO2 as a carbon source
• Ecology 


  the study of the interactions between living organisms and the world around them
• Ecosystem 


  refers to the interactions between living organisms and their nonliving environment.
• Metabolism 


  refers to all of the chemical reactions that occur in a cell
• metabolic reactions

  chemical reactions that occur in a cell are referred to
• metabolic enzymes


  Metabolic reactions are enhanced and regulated by enzymes known as
• enzymes


  biologic catalysts
• enzymes


  proteins that either cause a particular chemical reaction to occur or accelerate it
• enzymes


  are specific, in that they catalyze only one particular chemical reaction
• substrate 


  A particular enzyme can exert its effect on only one particular substance, known as
• Endoenzymes


  enzymes produced within a cell that remain within the cell to catalyze reactions
• Exoenzymes 


  produced within a cell and then released outside of the cell to catalyze extracellular reactions
• metabolite


  any molecule that is a nutrient, an intermediary product, or an end product in a metabolic reaction
• catabolism and anabolism


  Metabolic reactions fall into two categories
• Catabolism 


  refers to all catabolic reactions in a cell.
• Anabolism


  refers to all anabolic reactions in a cell
• Catabolic reactions


  involve the breaking down of larger molecules into smaller ones
• Catabolic reactions 


  cell’s major source of energy
• Anabolic reactions


  involve the assembly of smaller molecules into larger molecules, requiring the formation of bonds
• bonds


  represent stored energy
• adenosine triphosphate


  special molecules where energy can be temporarily stored in high-energy bonds
• ATP molecules 


  the major energy-storing or energy-carrying molecules in a cell
• adenosine diphosphate 


  When ATP is used as an energy source, it is hydrolyzed to
• adenosine monophosphate 


  If necessary, ADP can be used as an energy source by hydrolysis to
• Energy


  required not only for metabolic pathways but also for growth, reproduction, sporulation, and movement of the organism, as well as active transport of substances across membranes.