Discovering Cells Life Science Chapter 2 Section 3 pp

What are Cells? Cells are the basic units of structure and function in living things Cells are the basic units of structure and function in living things Structure: what living things are made of Structure: what living things are made of Function: the processes that keep an organism alive Function: the processes that keep an organism alive One square cm of skin contains over One square cm of skin contains over 100,000 cells 100,000 cells Skin Cells

First Observation of Cells MICROSCOPE MICROSCOPE is an instrument that makes small things look big is an instrument that makes small things look big The invention of the microscope made it possible for … The invention of the microscope made it possible for … people to discover people to discover and learn about cells

First Observation of Cells A SIMPLE microscope has only one lens A SIMPLE microscope has only one lens A COMPOUND microscope A COMPOUND microscope has more than one lens has more than one lens

Robert Hooke In 1633, one of the first to observe cells with a microscope that he made In 1633, one of the first to observe cells with a microscope that he made Hooke used his microscope to look at the structure of a thin slice of cork (the bark of the cork oak tree) He felt the small empty spaces looked like tiny rectangular rooms, so he called the empty spaces “ cells ” which is a word meaning “small rooms.”

Cork Cells as Drawn by Hooke

Cork Cells under 100x Magnification

Anton van Leeuwenhoek (pronounced 'vahn Laywenhook') Dutch tradesman and scientist from the Netherlands. Dutch tradesman and scientist from the Netherlands. He is commonly known as "the Father of Microbiology". He is commonly known as "the Father of Microbiology". Using his handmade microscopes, he was the first to observe and describe single celled organisms Using his handmade microscopes, he was the first to observe and describe single celled organisms

Anton van Leeuwenhoek Uses the microscope he built to look at: Drops of lake water Drops of lake water Scrapings from teeth and gums Scrapings from teeth and gums Water from rain gutters Water from rain gutters

“Little Animals” Anton van Leeuwenhoek saw moving little animals he called: AnimalculesAnton van Leeuwenhoek saw moving little animals he called: Animalcules

Schleiden, Schwann, and Virchow 1838 Schleiden concludes: ALL plants are made of cells 1838 Schleiden concludes: ALL plants are made of cells 1839 Schwann concludes: ALL animals are made of cells 1839 Schwann concludes: ALL animals are made of cells Therefore, ALL LIVING THINGS ARE MADE OF CELLS Therefore, ALL LIVING THINGS ARE MADE OF CELLS However, no one could explain where cells come from However, no one could explain where cells come from 1855 Virchow writes: New cells are only formed from cells that already exist… 1855 Virchow writes: New cells are only formed from cells that already exist… or ALL CELLS COME FROM CELLS or ALL CELLS COME FROM CELLS

The Cell Theory Schleiden, Schwann, Virchow and others helped develop the cell theory. Schleiden, Schwann, Virchow and others helped develop the cell theory. Cell Theory Cell Theory is a widely accepted explanation for the relationship between cells and living things. THE CELL THEORY STATES THE FOLLOWING: THE CELL THEORY STATES THE FOLLOWING: All living things are composed of cells All living things are composed of cells Cells are the basic units of structure and function in living things. Cells are the basic units of structure and function in living things. All cells are produced from other cells. All cells are produced from other cells.

Microscope Timeline 1590 one of the first compound microscope- uses two lenses

Microscope Timeline 1660 Hooke’s compound microscope uses light to help see

Microscope Timeline 1674 Leeuwenhoek’s simple microscope can magnify 266 times

Microscope Microscope Timeline 1886 Modern Compound Light Microscope can magnify up to 1,000 times

Microscope Timeline 1933 Transmission Electron Microscope (TEM) using electrons, it can magnify up to 500,000 times

Microscope Timeline 1965 SEM -Scanning Electron Microscope can see in 3D and magnify up to 150,000 times

Microscope Timeline 1981 STM Scanning Tunneling Microscope can magnify up to 1,000,000 times

Light and Electron Microscopes The lenses in light microscopes magnify an object by The lenses in light microscopes magnify an object by bending the light bending the light that passes through them

Compound Microscope Magnification 20x 30x Total magnification is equal to the two lenses multiplied together So 20 x 30 = 600 times larger

Electron Microscope A microscope that uses a beam of electrons instead of light to produce a magnified image is called an ELECTRON microscope ELECTRON

Hidden Worlds… An image of a streptococcus bacteria taken by a scanning electron microscope. Magnified around 2,000,000x Fly Foot

Alien Life??? Weevilpyralidae moth Electric guitar string

You Know These!!! Edge of a dime Sponge (only 23x) leaf Snowflake Strand of hair