Cells

Scientists important to the cell theory

Booke:

  • First person to see cells: 1665
  • Named them after a room monks prayed in

Leeuwenhoek:

  • First person to see living cells: 1675
  • Used the scrapings off peoples teeth

Schleiden and Schwann:

  • First person to observe that plants have cells: 1838 (Schleiden)
  • First person to observe that animals have cells: 1838 (Schwann)

Virchow:

  • First person to say that all cells come from preexisting cells :1855

Cell theories

Traditional:

  • All living things are made of cells
  • Cells are the basic unit of life
  • All cells come from preexisting cells

Modern:

  • Energy flow within cells
  • Contains DNA
  • Similar species have similar chemical composition

Prokaryotic cells

Control center:

  • No nucleus
  • Genetic info (DNA) is “bunched up” in the cytoplasm in the nucleoid region

Organelles:

  • No organelles that are membrane bound
  • Do have ribosomes

Genetic info:

  • DNA is circular and called plasmid
  • Long molecule shaped like a rubber band

Types of cells:

  • Bacteria
  • Archaebacteria and Eubacteria

Eukaryotic cells

Control center:

  • Nucleus in the center region
  • Controls all cells activities
  • Easy to see

Organelles:

  • Surrounded by membranes
  • Separate structures
  • Easy to see

Genetic info:

  • DNA is linear
  • Stored in the nucleus
  • In form of chromatin

Types of cells:

  • Anything but bacteria
  • Plants
  • Animals
  • Fungi
  • protists