BIOL 172 Chapter 27: BIOL 172 Chapter 27 (27) Notes
Document Summary
In a hypertonic environment, most prokaryotes lose water and shrink away from their wall (plasmolyze). In eukaryotes that have cell walls, such as plants and fungi, the walls are usually made of cellulose or chitin. Encloses the entire bacterium and anchors other molecules that extend from its surface. a technique in which scientists can categorize many bacterial species according to differences in cell wall composition. Samples are first stained with crystal violet dye and iodine, then rinsed in alcohol, and finally stained with a red dye such as safranin. The structure of a bacterium"s cell wall determining if a patient"s infection is due determines the staining response. A valuable tool in medicine for quickly to gram-negative or to gram-positive bacteria. Gram-negative bacteria tend to be more resistant than gram-positive species to antibiotics because the outer membrane impedes entry of the drugs. However, certain gram-positive species have virulent strains that are resistant to one or more antibiotics.
