Cell Bioiogy

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...