Aerobic and Anaerobic Growth and Metabolism
The growth of most medically important organisms is enhanced by the presence of oxygen, which acts as the hydrogen acceptor in the final stages of energy production catalyzed by the…
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Bacterial Metabolism
Bacteria cannot reproduce without a source of energy and the building blocks of cellular constituents (e.g. amino acids, carbohydrates, lipids). Minimum requirements for growth are a source of carbon and…
Read More →Growth Cycle in Microbiology
Growth Cycle Bacteria reproduce by binary fission: one cell divides to form 2 progeny cells. This results in exponential (logarithmic) growth. 1. Number of cells 1 2 4 8 16…
Read More →Metabolism in Microbiology
Learning Objectives: You should be able to: explain how bacteria reproduce and the potential effects of a short vs. a long generation time on the production of disease. describe the…
Read More →Bacterial Classification and Structure Study Questions
Study Questions List 8 major structural differences between prokaryotes and eukaryotes and/or draw a picture of each cell type that shows these differences (don’t forget to label the structures). is…
Read More →Specialized Structures Outside of the Cell Wall
Capsule Gelatinous layer surrounding the bacterial cell; gives many bacterial colonies a mucoid appearance. Composed of polysaccharide (except in Bacillus anthracis) which varies among bacteria and is used in identification.…
Read More →Cytoplasmic (Cell) Membrane, Mesosome and Cytoplasm
1. Cytoplasmic (Cell) Membrane Located just inside the peptidoglycan layer. Phospholipid bilayer similar to eukaryotic membranes, but does not contain sterols (except Mycoplasma species). Functions: transport of molecules into cell…
Read More →Outer Membrane of Gram-negative Cells
like a stiff “canvas sack” around the bacterial cell. maintains cell structure. is a permeability barrier to large molecules (like lysozyme) and hydrophobic molecules; also provides protection from adverse environments…
Read More →The Structure of Bacterial Cells
Structure Chemical Composition Function Essential Components Cell Wall Peptidoglycan Outer membrane of Gram- negative bacteria Surface fibers of Gram- positive bacteria Sugar…
Read More →Medically important bacteria that cannot be seen in the Gram stain
Name Reason Alternative Microscopic Approach Mycobacteria(Ex. M. tuberculosis) Too much lipid in cell wall so dye cannot penetrate Acid-fast stain Treponema pallidum Too thin to see Dark-field microscopy or fluorescent…
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