Biology  5/e   Raven/Johnson
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Prokaryotic cell structure: Prokaryotes have a chemically complex cell wall. They have chromosomes of double-stranded DNA in a closed ring, but the chromosomes are not contained in a nucleus. Eukaryotes lack internal compartmentalization and, though some have chlorophyll, they lack chloroplasts. Prokaryotes also lack other typical eukaryotic structures such as a Golgi complex, mitochondria, and endoplasmic reticulum. Prokaryotes reproduce only by binary fission.

Bacterial flagella: The flagella of bacteria consists only of the protein flagellin and lack the structure of eukaryotes. The bacterial flagella rotate like a propeller.

Bacterial cell division: Before cell division, the bacterium replicates its genome and collects both copies near a structure called a mesosome. Soon thereafter, the cell is cleaved by ingrowth of the cell wall dividing the cell into two cells, each with a duplicate genome.

Bacterial metabolism and chemoautotrophy: The world in which bacteria first lived lacked atmospheric oxygen. Bacteria utilized chemoautotrophy to secure energy metabolizing sulfur and nitrogen compounds and fixing free nitrogen, all of which bacteria do today.

Bacterial photosynthesis: As oxygen became available, bacteria evolved aerobic respiration and photosynthesis, utilizing a variety of photosynthetic pigments such as carotenoids and chlorophylls.

Transduction and bacterial conjugation: Bacteria are capable of transferring genetic material from one to another through a tubular projection called a pilus. This process enables one population to transfer pathogenic characteristics to a previously non-virile population. Such an alteration of characteristics is called transduction.

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