Bio211

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Mariebs Human Anatomy and Physiology
Marieb w Hoehn
Chapter 3 Cells The Living Units Lecture 5 Video
Part I
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Lecture Overview

• Specialization and differentiation of cells
• General characteristics of cells
• The cell membrane
• Movement of substances into and out of the cell
• Osmotic pressure and tonicity
• Overview of cellular organelles

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Cells Are Specialized
Figure from Martini Ober, Visual Anatomy
Physiology, Human AP, 1st edition, 2010
Differentiated Specialized

• vary in size
• vary in shape
• vary in function
• measured in micrometers

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A Composite Cell

• hypothetical cell
• major parts
• nucleus
• cytoplasm
• cell membrane

Figure From Marieb Hoehn, Human Anatomy
Physiology, 9th ed., Pearson
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Cell Membrane

• outer limit of cell isolates cell

• controls what moves in and out of cell -
  selectively permeable

• self-sealing

• phospholipid bilayer
• water-soluble heads form outer surfaces
• water-insoluble tails form interior
• permeable to lipid-soluble substances only

• cholesterol stabilizes the membrane

• proteins
• receptors
• pores, channels, carriers
• enzymes
• CAMS
• self-markers

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Cell Membranes
Figure from Martini, Anatomy Physiology,
Prentice Hall, 2001
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A Transmembrane Protein
Figure from Alberts et al., Essential Cell
Biology, Garland Publishing, 1998
Hydrophilic channel
Membrane Lipids