Microscopes
History Invented in the late 1500s – Compound microscope (2+ lenses) – Used natural light, magnified 20-30x
Robert Hooke (1665) Compound light microscope viewed cork (dead oak cells) Viewed shapes coined them “cells”
Antony van Leeuwenhoek (1600s) Father of microscopy and microbiology Built simple light microscope (one lens) – Improvement: 275x magnification Viewed water – Noticed Protists, worms, etc. Observed blood and sperm
Matthias Schleiden & Theodore Schwann Schleiden (1830s) – concluded all plants made of cells Schwann (1830s) – concluded all animals made of cells
Cell Theory All organisms composed of cells Cell = basic unit of organization in organisms All cells come from pre-existing cells
Electron Microscope (1940s) Beam of electrons instead of light Magnifies up to 500,000x 2 types – Scanning electron microscope (SEM) Surfaces in 3D – Transmission electron microscope (TEM) Structure inside cells
Scanning Tunneling Microscope (STM) See atoms on surface of molecules – 100,000,000x
Compound Light Microscope Lamp light 1500x Calculate Magnification: eyepiece x objective (always 10x) (varies) Example: Objective lens set to 4x, what is total magnification of microscope?