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LECTURE PRESENTATIONS For CAMPBELL BIOLOGY, NINTH EDITION
Jane B. Reece, Lisa A. Urry, Michael L. Cain, Steven A. Wasserman, Peter V. Minorsky, Robert B. Jackson
Chapter 6
A Tour of the Cell
Lectures by Erin Barley Kathleen Fitzpatrick
© 2011 Pearson Education, Inc.
Overview: The Fundamental Units of Life
• All organisms are made of cells • The cell is the simplest collection of matter that can be alive • Cell structure is correlated to cellular function • All cells are related by their descent from earlier cells
© 2011 Pearson Education, Inc.
Figure 6.1
Concept 6.1: Biologists use microscopes and the tools of biochemistry to study cells
• Though usually too small to be seen by the unaided eye, cells can be complex
© 2011 Pearson Education, Inc.
Microscopy
• Scientists use microscopes to visualize cells too small to see with the naked eye • In a light microscope (LM), visible light is passed through a specimen and then through glass lenses • Lenses refract (bend) the light, so that the image is magnified
© 2011 Pearson Education, Inc.
• Three important parameters of microscopy
– Magnification, the ratio of an object’s image size to its real size – Resolution, the measure of the clarity of the image, or the minimum distance of two distinguishable points – Contrast, visible differences in parts of the sample
© 2011 Pearson Education, Inc.
Figure 6.2
10 m Human height 1m Length of some nerve and muscle cells Chicken egg 1 cm Frog egg 1 mm Human egg Most plant and animal cells 10 m Nucleus Most bacteria Mitochondrion Light microscopy
0.1 m
100 m
Unaided eye
1 m
100 nm
Smallest bacteria Viruses Ribosomes
Superresolution microscopy
10 nm
Proteins
Lipids 1 nm Small molecules Atoms
0.1 nm
Electron microscopy
Figure 6.2a
10 m Human height 1m Unaided eye Length of some nerve and muscle cells Chicken egg 1 cm Frog egg 1 mm
0.1 m
100 m
Human egg
Figure 6.2b
1 cm...