MODULE 3 – SYSTEMATIC MICROBIOLOGY

CHARACTERISTICS OF MICRO ORGANISMS

All micro-organisms participate in six life processes as follows – 

• Metabolize: Breakdown nutrients for energy or extract energy from the environment.

• Be responsive: React to internal and external environmental changes.

• Move: Whether it is the entire organism relocating within its environment, cells within that organism or the organelles inside those cells.

• Grow: Increase the size or number of cells.

• Differentiate: The process where cells that are unspecialized become specialized. (An example would be a single fertilized human egg, developing into an individual). Prokaryotic cells do not differentiate.

• Reproduce: Form new cells to create a new individual.

PROKARYOTIC CELLS

A prokaryotic cell is a cell that does not have a true nucleus. The nuclear structure is called a nucleoid. The nucleoid contains most of the cell’s genetic material and is usually a single circular molecule of DNA. Karyo- is Greek for “kernel.” A prokaryotic organism, such as a bacterium, is a cell that lacks a membrane-bound nucleus or membrane-bound organelles. The exterior of the cell usually has glycocalyx, flagellum, fimbriae, and pili