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Bacteria. Prokaryotic Cells: Chapter 17. Name two scientists that can be given credit for discovering a new world of microscopic organisms that include the bacteria: Anton van Leeuwenhoek Robert Hooke. Bacteria- Prokaryotic Cells. Where on Earth would you go to find prokaryotic organisms?
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Bacteria Prokaryotic Cells: Chapter 17
Name two scientists that can be given credit for discovering a new world of microscopic organisms that include the bacteria: • Anton van Leeuwenhoek • Robert Hooke Bacteria- Prokaryotic Cells
Where on Earth would you go to find prokaryotic organisms? • Almost everywhere! • Even in the air and soil. • They grown in colonies so that they can be seen by the naked eye. Bacteria- Prokaryotic Cells
Review!!! • Name the two kingdoms into which all prokaryotes can be classified: • Archaebacteria • Eubacteria Bacteria- Prokaryotic Cells
Bacteria, which are much larger than viruses, are measured in micrometers instead of nanometers. • How large is a micrometer? • 1μm = 0.001mm or 0.000001 m • The range in size for a typical prokaryotic bacterium is 1 - 10 μm. Bacteria- Prokaryotic Cells
E. coli Not Typical → Eubacteria The cell wall can be used to ID the bacteria by Gram Staining.
One example of eubacteria are the cyanobacteria (a.k.a. blue/green algae). • Give three characteristics of cyanobacteria: • Photosynthetic (autotrophic) • Blue-green colour (two pigments: chlorophyll a and phycocyanin) • Can survive in salt water and other harsh environments like hot water Eubacteria
Two ways that archaebacteria are different than eubacteria: • Eubacteria have carbohydrates found in cell walls that archaebacteria don’t have. • Eubacteria also have lipids in cell membranes that archaebacteria don’t have. • The two kinds of bacteria also have different ribosomes. Archaebacteria
The simplest way to identify different types of bacteria is by their shape. • Name the three basic shapes of bacteria in their singular and plural forms: • Round shape:coccus (sing.) cocci (pl.) • Rod shape:bacillus (sing.) bacilli (pl.) • Spiral shape: spirillum (sing.) spirilla (pl.) Bacterial Morphology
Identify the following bacteria by their names: • Streptobacilli: chain of rod shaped bacteria Bacterial Morphology
Identify the following bacteria by their names: • Staphylococci: clusters of round shaped bacteria Bacterial Morphology
Identify the following bacteria by their names: • Monotrichous: bacillus with single flagellum Bacterial Morphology
Identify the following bacteria by their names: • Amphitrichous: bacillus with 2 flagella Bacterial Morphology
Many bacteria can be so close together in appearance that shape alone does not help us to identify them. • Sometimes a special stain is used on the bacteria to give us more information about different bacteria. • One technique is called Gram Staining. Cell Wall
This technique is named after Hans Christian Gram. • There are 2 special dyes: • Crystal Violet – purple stain • Safranine – red dye Cell Wall
Bacterial cells with only 1 thick layer of carbohydrate and proteins take up the crystal violet and look purple – Gram + • Bacteria with a second layer of carbohydrates and lipids take up safranine and look red – Gram - Cell Wall