the cell. 7.1 cell discovery and cell theory how do we study cells? with microscopes!!!!!!
TRANSCRIPT
The Cell
7.1 Cell discovery and cell theory
How do we study cells?
With
MICROSCOPES!!!!!!
7.1 Objectives Identify the parts of a microscope Match scientists with key discoveries Compare light and electron
microscopes Identify the 3 parts of cell theory Explain the main differences between
eukaryotic and prokaryotic cells
Compound Light
Microscopes (what we will use)
The guys who started it all… Zacharias and Hans Janssen invent
the world's first 2 lens (compound) microscope in 1590.
The guys who started it all… 1665 Robert Hooke
Looking at cork Chambers (named
them cells) Anton van
Leeuwenhoek Single lens
microscope Pond water 1st to discover living
cells“animalcules” (protists)
Why the long gap between inventions?
Few advancement in the mid 19th century Spontaneous Generation (widely accepted,
traditional belief that life arises from nonlife) Examples:
Mice were created from damp hay and corn in a dark corner Maggots/Flies came from
rotting meat Mud could give rise to worms,
insects, and fish
19th Century Advancement Spontaneous Generation = doubters Louis Pasteur
Disproved and replaced theory with… Theory of Biogenesis (states that only living
organisms can produce other living organisms)
Designed an experiment to show this was true even for microorganisms
Development of the Cell Theory
Matthias Schleiden: (1838- German Botanist) plant parts are made of cells
Theodor Schwann: (1839- German physiologist) animal tissues are composed of cells.
Johannes Purkinje (1840) First to observe cell division First to observe the living contents of a cell
Development of the Cell Theory Rudolf Virchow (1858- German
physician) concluded that cells must arise from
preexisting cells
Because of them, today we have…
Advancing technology Light microscopes
Electron microscopes Early 1900’s Higher resolution
Scanning probe microscopy
Fluorescence and light microscopy Uses fluorescence and phosphorescence
in addition to, reflection and absorption
What do you know about cells?
Cell Theory: 3 parts 1. All living things are made of cells
Composed of cells (Matthis Schleiden 1838- plants were made of cells; Theodor Schwann 1839-animals too!)
2. Cells are basic unit of structure and function of living things
3. New cells are made from existing cells (Rudolf Virchow 1855)
All Cells… Surrounded by a cell barrier (cell
membrane) Carry biological information at some
point (DNA) Vary in size and shape
Two different types Prokaryotic and Eukaryotic
Prokaryotic vs. Eukaryotic Prokaryotes Eukaryotes
• “Pro” = Before• Karyon =
nucleus
• “E = True
• Karyon = nucleus
• True nucleus
• Size: Large/Complex
• Membrane bound organelles
• Membrane bound nucleus with linear DNA
• Some have cell walls
• Multicellular or unicellular
Found in Kingdoms:• Animalia• Plantea• Protista• Fungi
• No true nucleus
• Size: Small/primative
• No membrane bound organelles
• DNA is small and in a ring
• Cell wall
• Unicellular-colonies
• Free Ribosomes (small)
Found in Kingdoms:
• Archaea • Bacteria