The Cell Theory  All organisms are composed of one or more cells. 7.1 Cell Discovery and Theory Cellular Structure and Function  The cell is the basic unit of structure and organization of organisms. Chapter 7  All cells come from preexisting cells.

Prokaryotic Cell  Simple structure Cellular Structure and Function  Contains a plasma membrane  Does not contain membrane-bound organelles 11,000x 7.1 Cell Discovery and Theory Chapter 7

Eukaryotic Cell  More complex structure Cellular Structure and Function  Contains a plasma membrane  Contains membrane- bound organelles 400x 7.1 Cell Discovery and Theory Chapter 7

Plasma Membrane  Thin, flexible boundary between the cell and its environment 7.2 The Plasma Membrane Cellular Structure and Function  Allows nutrients into the cell  Allows waste to leave the cell Chapter 7

Selective Permeability Cellular Structure and Function  The plasma membrane controls the movement of substances into and out of the cell. Plasma Membrane  Controls the amount of a substance entering the cell  Controls the amount of a substance leaving the cell 7.2 The Plasma Membrane Chapter 7

 The plasma membrane is composed of the phospholipid bilayer. Cellular Structure and Function  A phospholipid molecule is composed of a glycerol backbone, two fatty acid chains, and a phosphate group. 7.2 The Plasma Membrane Chapter 7

Fluid Mosaic Model Cellular Structure and Function  The phospholipid bilayer allows other molecules to “float” in the membrane. Other Components  Proteins  Cholesterol  Carbohydrates 7.2 The Plasma Membrane Chapter 7

Proteins Cellular Structure and Function  Transmit signals inside the cell  Act as a support structure  Provide pathways for substances to enter and leave 7.2 The Plasma Membrane Chapter 7

Cholesterol Cellular Structure and Function  Prevents fatty acid tails from sticking together 7.2 The Plasma Membrane Chapter 7

Carbohydrates Cellular Structure and Function  Identify chemical signals 7.2 The Plasma Membrane Chapter 7