Unformatted text preview: Topic 3 Fundamentals of Microbiology (Biology 140) Course notes Dr. Josh D. Neufeld Learning Objectives: An introduction to the diversity of microorganisms, cell morphology, and structure. Microbes make a living in many different ways. This is reflected in the metabolic diversity that is seen. The metabolic options for obtaining energy are shown in Figure 2.18: from organic chemicals (chemoorgano
), inorganic chemicals (chemolitho
), or from light (photo
). Cells also require carbon. Some microorganisms obtain their carbon from organic compounds, and these are called heterotrophic. Other microorganisms obtain their carbon from CO2 and these are termed autotrophic. All organisms can be classified nutritionally by a combination of [energy source][carbon source] and the term [
troph]. Thus, Cyanobacteria are categorized as photoautotrophs for their ability to use light energy and consume CO2 into biomass. In the second half of the course, we will investigate the phylogenetic diversity of the microbial world in more detail. Figures 2.19 and 2.28 will serve as an introduction to the Bacteria and the Archaea. Figure 2.32 covers the Eukarya, although we will not focus much on microeukaryotes in this course. Prokaryotes come in different shapes (=morphologies): coccus, rod, spirillum, spirochaete, appendaged, filamentous. See Figure 4.1. Prokaryotes also come in different sizes. See Table 4.1. Note the photomicrographs of the giant prokaryotes in Figure 4.2. For a discussion of large bacteria, see the review published by Schulz and Jørgensen published in Annual Review of Microbiology (see pdf in lecture folder). Surface Area vs. Volume (see Figure 4.3).
Size affects rate of nutrient and waste transport across the cell membrane.
Small size results in more efficient exchange of nutrient and waste, support of higher metabolic rate. ...
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