7-1 Life is CELLULAR Federoff

Discovery of the Cell Microscopes allowed a new world to open up. – Started in the late 1500’s with eyeglass makers Robert Hooke (1665) – Englishman – Studied Cork – Termed cells “cells” because of their resemblance to monastery rooms.

Discovery of the Cell (cont.) Anton van Leewenhoek – Same time as Hooke – Documented first LIVING and moving cells we know today as microorganisms

Cell Theory Schleiden, Schwann and Virchow – Scientists contributors States that: – All living things are made of cells – Cells are the basic structure and function in all living things – New cells come from existing cells

Exploring the cell - Microscopes Light Microscopes – Have an objective and eyepiece (ocular) lens – Compound magnification – LIMITS Detail 1000x magnification Requires a stain Thin specimen for light to pass through

Microscopes (cont.) Electron Microscopes – Higher Resolution – Can view DNA and Viruses – Scanning and Transmission – LIMITS Must chemically preserve Needs to be DEAD Need to add false color

Scanning

Transmission

Cell Types Lots of variety in size, shape and function All contain DNA and a cell membrane 2 Types – Eukaryotes – have DNA in a nucleus – Prokaryotes – Do not have a nucleus to contain their DNA

Prokaryotes Smaller Simpler Doesn’t separate DNA with a nucleus Unicellular Ex. Bacteria

Eukaryotes Larger More complex DNA in nucleus Great variety Unicellular or Multicellular Ex. Your cells