Chapter 7.1 Cells

Image credit: Sibi on Flickrhttp://www.flickr.com/photos/beebee/200316216/in/set-72057594081382862/

Goal 1:

Explain the Cell theory and its evolution

• Cell Theory

1. All living things composed of cells

2. Cells are the basic units of structure and function in living things

3. New cells are produced from existing cells

• Robert Hooke 1665– Microscope – First to observe cells

Image credit: PD-govhttp://en.wikipedia.org/wiki/Image:Hooke_Microscope-03000276-FIG-4.jpg

Image credit: Martin LaBar on Flickrhttp://www.flickr.com/photos/martinlabar/66177481/

• Anton van Leeuwenhoek 1674

– Single-celled Protista

Image credit: Dr. Ralf Wagner on wikipedia commonshttp://en.wikipedia.org/wiki/Image:Chaos_diffluens.jpg

• Matthias Schleiden 1838– All plants are made up of cells

Image credit: PD-personalhttp://en.wikipedia.org/wiki/Image:Matthias_Jacob_Schleiden.jpg

• Theodore Schwann 1839 – Animals are made up of cells

Image credit: PD-oldhttp://en.wikipedia.org/wiki/Image:Schwann_Theodore.jpg

• Rudolph Virchow 1855 – New cells from division of existing cells

Image credit: PD-oldhttp://en.wikipedia.org/wiki/Image:Rudolf_Virchow_by_Hugo_Vogel,_1861.JPG

Image credit: PD-oldhttp://en.wikipedia.org/wiki/Image:Telophase.jpg

• Cell Theory

1. All living things composed of cells

2. Cells are the basic units of structure and function in living things

3. New cells are produced from existing cells

Goal 2:

Discuss how researchers explore the living cell

1. Modern light microscopes

– Fluorescent “labels”– Molecules

Image credit: PD-govhttp://en.wikipedia.org/wiki/Image:FluorescentCells.jpg

2. Confocal light microscopes

– lasers– High resolution – 3-D images

Image credit: Pawel Jasnos

http://en.wikipedia.org/wiki/Image:Tetrachimena_Beta_Tubulin.png

Tubulin protein marked in Tetrachimena sp.

3. High resolution video– Movies of cell activities

Image credit: PD-gov

http://physics.nist.gov/Divisions/Div842/Gp4/Tweezers/Images/Liposomefusion.jpg

Video of liposome fusion

4. Transmission Electron Microscopy (TEM)– Beams of electrons are passed through a

thin slice of an object– Objects too small for light microscopes

Image credit: PD-personal by Allonweiner

http://en.wikipedia.org/wiki/Image:Bacillus_subtilis.jpg

TEM image of Bacterium Bacillus subtilis

5. Scanning Electron Microscopy (SEM)

– Beams of electrons scanned over surface of an object

– 3-D images

Image credit: PD-personal by Dartmouth Electron Microscope Facility

http://en.wikipedia.org/wiki/Image:Misc_pollen.jpgPollen Grains

6. Scanning Probe Microscopy (SPM)– Scans objects with probe – 3-D image– Open air with samples in solution– Probes are needles with a tip of one atom (wow! That’s

small!)

Goal 3:

Distinguish between eukaryotes and prokaryotes

• Characteristics of ALL cells

– Surrounded by a cell membrane

– Genetic information in the form of DNA

Image credit: Ah Pao on Flickr

http://www.flickr.com/photos/ah_pao/2590858936/

• Prokaryotes– No nucleus– Simple– Small– Single cell

organisms– Bacteria

Image credit: Nutloaf on Flickr

http://flickr.com/photos/83371410@N00/1644090403

Salomonella bacteria invades a human cell

Image credit: PD-personal LadyofHats on wikipedia

http://commons.wikimedia.org/wiki/Image:Prokaryote_cell_(temp_PNG).png

• Eukaryotes– Contain nucleus!! – Complex, organelles– Large– Single-celled or multi-cellular

Image credit: PD-personal LadyofHats on wikipedia

http://commons.wikimedia.org/wiki/Image:Animal_cell_structure_en.svg

Image credit: Wenche Eikrem and Jahn Throndsen

http://en.wikipedia.org/wiki/Image:Ostreococcus_RCC143.jpg