BIOL 2051 Chapter : Chapter 2
Document Summary
Size of prokaryotes: prokaryotes are generally smaller than eukaryotes. Small size allows nutrients to reach all parts of cell quickly. Prokaryotic cells can be as small as 0. 2 m. The smallest eukaryotic cells are 2 m: cocci - typically have diameter of 2 m, some microbiologists have proposed that bacteria smaller than 0. 2 m exist in nature, cells referred to as nanobacteria. Rigid spiral-shaped bacteria are called sprilla (singular spirillum) Microscopy: simple microscopes, one lens, magnify 50 300x, compound microscopes, multiple lenses, much higher magnification, ones in 2051 lab magnify 1000x. Lens system of compound microscopes: condenser lens located between source and specimen, focuses light rays up through specimen, objective lens systems, closest to specimen, typical scope has 10, 40, & 100x objective lenses. Allows higher magnification and resolution: ocular lens system, closest to the eye, typically magnify, each ocular has multiple lenses.