2. Learning Objectives
• Describe the properties of a cell.
• Identify the components common to all cells.
• Compare and contrast the cells that characterize the three domains of
life.
• Explain how the chemical structure of phospholipids enables them to
form a bilayer in water.
• Explain why a biological membrane has selective permeability.
• Identify different functions of membrane proteins.
• Identify the functions of the organelles in eukaryotic cells.
• Describe how organelles interact in carrying out a cell’s function.
• Compare and contrast the structure and function of cytoskeletal
proteins.
• Compare and contrast different cell junctions in animal cells.
• Explain the function of plasmodesmata in plant cells.
6. What do you observe?
Radius = 1 cm Radius = 4 cm
Surface area = 12.6 cm2 Surface area = 201.1 cm2
Volume = 4.2 cm3 Volume = 268.1 cm3
Heat Gain Heat LossSurface-to volume ratio
Thermo-
How?
Why are cells so
small?
7. Why Are Cells So Small?
Section 3.1 Figure 3.4
Smaller cells have more
_____________relative
to their _________.
High surface area allows
the cell to
8. Different Cell Types Characterize
Life’s Three Domains
Section 3.2 Figure 3.5
Unique features distinguish the
Bacteria, Archaea, and Eukarya.
9. The Anatomy of a Bacterium
Section 3.2 Figure 3.6
Bacteria are
10. The Anatomy of an Animal Cell
Section 3.2 Figure 3.8
Animal cells are
11. The Anatomy of a Plant Cell
Section 3.2 Figure 3.9
Plant cells are
12. A Membrane Surrounds Each Cell
Section 3.3 Figure 3.10
Cell membranes are
composed of