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Chapter 7 Cellular Structure and Function 7.1 Cell Discovery and Theory The Cell Theory All organisms are composed of one or more cells. The cell is the basic unit of structure and organization of organisms. All cells come from preexisting cells. Cell division Important People and Events • Robert Hooke – First coins the term “cells” – Saw first cells in cork • Anton van Leeuwenhoek – discovers singlecelled organisms • Louis Pasteur and Robert Koch – pioneered study of bacteria • Development of scanning tunneling microscope in 1981 allows scientists to see atoms Chapter 7 Cellular Structure and Function 7.1 Cell Discovery and Theory Light Microscopes Utilizes a series of glass lenses and visible light to magnify an image Magnifies images up to 1,000 times the actual size Chapter 7 Cellular Structure and Function 7.1 Cell Discovery and Theory Electron Microscopes Utilizes magnets to aim a beam of electrons at a cell to produce an image Magnifies images up to 500,000 times the actual size 9560x Chapter 7 Cellular Structure and Function 7.1 Cell Discovery and Theory Prokaryotic Cell Essentially a simple structure Contains a plasma membrane Does not contain membrane-bound organelles Prokaryotic Cells are usually bacteria and other unicellular organisms. 11,000x Chapter 7 Cellular Structure and Function 7.1 Cell Discovery and Theory Eukaryotic Cell More complex structure Contains a plasma membrane Contains membranebound organelles 400x Eukaryotic Cells make up organisms such as animals, plants, algae and yeast. Chapter 7 Cellular Structure and Function 7.2 The Plasma Membrane Plasma Membrane Thin, flexible boundary between the cell and its environment Allows nutrients into the cell Allows waste to leave the cell Chapter 7 Cellular Structure and Function 7.2 The Plasma Membrane Selective Permeability 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 Chapter 7 Cellular Structure and Function 7.2 The Plasma Membrane The plasma membrane is composed of the phospholipid bilayer. A phospholipid molecule is composed of a glycerol backbone, two fatty acid chains, and a phosphate group. Chapter 7 Cellular Structure and Function 7.2 The Plasma Membrane Fluid Mosaic Model The phospholipid bilayer allows other molecules to “float” in the membrane. Other Components Proteins Cholesterol Carbohydrates Chapter 7 Cellular Structure and Function 7.2 The Plasma Membrane Proteins Transmit signals inside the cell Act as a support structure Provide pathways for substances to enter and leave Chapter 7 Cellular Structure and Function 7.2 The Plasma Membrane Cholesterol Prevents fatty acid tails from sticking together Chapter 7 Cellular Structure and Function 7.2 The Plasma Membrane Carbohydrates Identify chemical signals Tue., November 29th CLASSWORK / OBJECTIVES: • Journal • Go over study guide • Notes Ch. 7.3 • Cell Organelle Chart HOMEWORK: • Work on Cell Organelle Chart FOCUS QUESTION: Name and describe two types of microscopy. TURN IN: Study Guide 7.1 + 7.2