1. What You’ll Learn
Cells are the foundation for the development of all life forms. Birth, growth, death, and all life functions begin as cellular functions.
Chapter Intro-page 170

2. Endoplasmic Reticulum
Lysosomes
Nucleus
Plasma Membrane
Endoplasmic Reticulum
Mitochondrion
Chapter Intro-page 174

3. 7.1 Section Objectives – page 171
Relate advances in microscope technology to discoveries about cells and cell structure.
Compare the operation of a microscope with that of an electron microscope.
Identify the main ideas of the cell theory.
7.1 Section Objectives – page 171

4. Section 7.1 Summary – pages 171-174
The History of the Cell Theory
Before microscopes were invented, people believed that diseases were caused by curses and supernatural spirits.
As scientists began using microscopes, they quickly realized they were entering a new world–one of microorganisms.
Microscopes enabled scientists to view and study cells, the basic units of living organisms.
Section 7.1 Summary – pages

5. Section 7.1 Summary – pages 171-174
Development of Light Microscopes
The first person to record looking at water under a microscope was Anton van Leeuwenhoek.
The microscope van Leeuwenhoek used is considered a simple light microscope because it contained one lens and used natural light to view objects.
Section 7.1 Summary – pages

6. Section 7.1 Summary – pages 171-174
Development of Light Microscopes
Compound light microscopes use a series of lenses to magnify objects in steps.
These microscopes can magnify objects up to times.
Section 7.1 Summary – pages

7. Section 7.1 Summary – pages 171-174
The Cell Theory
Robert Hooke was an English scientist who lived at the same time as van Leeuwenhock.
Hooke used a compound light microscope to study cork, the dead cells of oak bark.
Cells are the basic building blocks of all living things.
Section 7.1 Summary – pages

8. Section 7.1 Summary – pages 171-174
The cell theory is made up of three main ideas:
All organisms are composed of one or more cells.
The cell is the basic unit of organization of organisms.
All cells come from preexisting cells.
Section 7.1 Summary – pages

9. Section 7.1 Summary – pages 171-174
Development of Electron Microscopes
The electron microscope was invented in the 1940s.
This microscope uses a beam of electrons to magnify structures up to times their actual size.
Section 7.1 Summary – pages

10. Section 7.1 Summary – pages 171-174
Development of Electron Microscopes
There are two basic types of electron microscopes.
The scanning electron microscope scans the surface of cells to learn their three dimensional shape.
The transmission electron microscope allows scientists to study the structures contained within a cell.
Section 7.1 Summary – pages

11. Section 7.1 Summary – pages 171-174
Two Basic Cell Types
Cells that do not contain internal membrane-bound structures are called prokaryotic cells.
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The cells of most unicellular organisms such as bacteria do not have membrane bound structures and are therefore called prokaryotes.
Section 7.1 Summary – pages

12. Section 7.1 Summary – pages 171-174
Two Basic Cell Types
Cells containing membrane-bound structures are called eukaryotic cells.
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Most of the multi-cellular plants and animals we know are made up of cells containing membrane-bound structures and are therefore called eukaryotes.
Section 7.1 Summary – pages

13. Section 7.1 Summary – pages 171-174
Two Basic Cell Types
The membrane-bound structures within eukaryotic cells are called organelles.
Each organelle has a specific function that contributes to cell survival.
Section 7.1 Summary – pages

14. Section 7.1 Summary – pages 171-174
Two Basic Cell Types
Separation of organelles into distinct compartments benefits the eukaryotic cells.
The nucleus is the central membrane-bound organelle that manages cellular functions.
Section 7.1 Summary – pages

15. Section 2 Objectives – page 175
Explain how a cell’s plasma membrane functions.
Relate the function of the plasma membrane to the fluid mosaic model.
Section 2 Objectives – page 175

16. Summary Section 2 – pages 175-178
All living cells must maintain a balance regardless of internal and external conditions. Survival depends on the cell’s ability to maintain the proper conditions within itself.
Summary Section 2 – pages

17. Summary Section 2 – pages 175-178
Why cells must control materials
The plasma membrane is the boundary between the cell and its environment.
Summary Section 2 – pages

18. Summary Section 2 – pages 175-178
It is the plasma membrane’s job to:
allow a steady supply of glucose, amino acids, and lipids to come into the cell no matter what the external conditions are.
remove excess amounts of these nutrients when levels get so high that they are harmful.
allow waste and other products to leave the cell.
Summary Section 2 – pages

19. Summary Section 2 – pages 175-178
This process of maintaining the cell’s environment is called homeostasis.
Selective permeability is a process used to maintain homeostasis in which the plasma membrane allows some molecules into the cell while keeping others out.
Summary Section 2 – pages

20. Summary Section 2 – pages 175-178
Plasma Membrane
Water
Summary Section 2 – pages

21. Summary Section 2 – pages 175-178
Structure of the Plasma Membrane
The plasma membrane is composed of two layers of phospholipids back-to-back.
Phospholipids are lipids with a phosphate attached to them.
Summary Section 2 – pages

22. Summary Section 2 – pages 175-178
Phosphate Group
The lipids in a plasma membrane have a glycerol backbone, two fatty acid chains, and a phosphate group.
Glycerol Backbone
Two Fatty Acid Chains
Summary Section 2 – pages

23. Summary Section 2 – pages 175-178
Makeup of the phospholipid bilayer
The phosphate group is critical for the formation and function of the plasma membrane.
Phosphate Group
Summary Section 2 – pages

24. Summary Section 2 – pages 175-178
Makeup of the phospholipid bilayer
The fluid mosaic model describes the plasma membrane as a flexible boundary of a cell. The phospholipids move within the membrane.
Summary Section 2 – pages

25. Summary Section 2 – pages 175-178
Other components of the plasma membrane:
Cholesterol plays the important role of preventing the fatty acid chains of the phospholipids from sticking together.
Cholesterol
Molecule
Summary Section 2 – pages

26. Summary Section 2 – pages 175-178
Other components of the plasma membrane:
Transport proteins allow needed substances or waste materials to move through the plasma membrane.
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Summary Section 2 – pages

27. Section 3 Objectives page 179
Understand the structure and function of the parts of a typical eukaryotic cell.
Explain the advantages of highly folded membranes.
Compare and contrast the structures of plant and animal cells.
Section 3 Objectives page 179

28. Section 3 Summary – page 179-187
Cellular Boundaries
The plasma membrane acts as a selectively permeable membrane.
Section 3 Summary – page

29. Section 3 Summary – page 179-187
The cell wall
The cell wall is a fairly rigid structure located outside the plasma membrane that provides additional support and protection.
Section 3 Summary – page

30. Section 3 Summary – page 179-187
Nucleus and cell control
Nucleolus
Chromatin
Nuclear Envelope
Section 3 Summary – page

31. Section 3 Summary – page 179-187
Assembly, Transport, and Storage
The endoplasmic reticulum (ER) is an organelle that is suspended in the cytoplasm and is the site of cellular chemical reactions.
Section 3 Summary – page

32. Section 3 Summary – page 179-187
Assembly, Transport, and Storage
Endoplasmic Reticulum (ER)
Ribosomes
Section 3 Summary – page

33. Section 3 Summary – page 179-187
Assembly, Transport, and Storage
Golgi Apparatus
Section 3 Summary – page

34. Section 3 Summary – page 179-187
Vacuoles and storage
Vacuoles are membrane-bound spaces used for temporary storage of materials. Notice the difference between vacuoles in plant and animal cells.
Plant
Cell
Vacuole
Animal
Cell
Section 3 Summary – page

35. Section 3 Summary – page 179-187
Lysosomes and recycling
Lysosomes are organelles that contain digestive enzymes. They digest excess or worn out organelles, food particles, and engulfed viruses or bacteria.
Section 3 Summary – page

36. Section 3 Summary – page 179-187
Energy Transformers:
Chloroplasts and energy
Chloroplasts are cell organelles that capture light energy and produce food to store for a later time.
Section 3 Summary – page

37. Section 3 Summary – page 179-187
Chloroplasts and energy
The chloroplasts belongs to a group of plant organelles called plastids, which are used for storage.
Chloroplasts contain green pigment called chlorophyll. Chlorophyll traps light energy and gives leaves and stems their green color.
Section 3 Summary – page

38. Section 3 Summary – page 179-187
Mitochondria and energy
Mitochondria are membrane-bound organelles in plant and animal cells that transform energy for the cell.
Section 3 Summary – page

39. Section 3 Summary – page 179-187
Mitochondria and energy
A mitochondria, like the endoplasmic reticulum, has a highly folded inner membrane. Energy storing molecules are produced on inner folds.
Section 3 Summary – page

40. Section 3 Summary – page 179-187
Structures for Support and Locomotion
Cells have a support structure called the cytoskeleton within the cytoplasm. The cytoskeleton is composed of microtubules and microfilaments. Microtubules are thin, hollow cylinders made of protein and microfilaments are thin solid protein fibers.
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41. Section 3 Summary – page 179-187
Cilia and flagella
Some cell surfaces have cilia and flagella, which are structures that aid in locomotion or feeding. Cilia and flagella can be distinguished by their structure and by the nature of their action.
Section 3 Summary – page

42. Section 3 Summary – page 179-187
Cilia and flagella
Cilia
Cilia are short, numerous, hair-like projections that move in a wavelike motion.
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43. Section 3 Summary – page 179-187
Cilia and flagella
Flagella are long projections that move in a whip-like motion. Flagella and cilia are the major means of locomotion in unicellular organisms.
Flagella
Section 3 Summary – page

44. Chapter Summary – Section 1
Main Ideas
Microscopes enabled biologists to see cells and develop the cell theory.
The cell theory states that the cell is the basic unit of organization, all organisms are made up of one or more cells, and all cells come from preexisting cells.
Chapter Summary – Section 1

45. Chapter Summary – Section 1
Main Ideas Continued
Using electron microscopes, scientists can study cell structure in detail.
Cells are classified as prokaryotic and eukaryotic based on whether or not they have membrane-bound organelles.
Chapter Summary – Section 1

46. Chapter Summary – Section 2
Main Ideas
Through selective permeability, the plasma membrane controls what enters and leaves a cell.
The fluid mosaic model describes the plasma membrane as a phospholipid bilayer with embedded proteins.
Chapter Summary – Section 2

47. Chapter Summary – Section 2
Main Ideas
Eukaryotic cells have a nucleus and organelles, are enclosed by a plasma membrane, and some have a cell wall that provides support and protection.
Cells make proteins on ribosomes that are often attached to the highly folded endoplasmic reticulum. Cells store materials in the Golgi apparatus and vacuoles.
Chapter Summary – Section 2

48. Chapter Summary – Section 3
Main Ideas Continued
Mitochondria break down food molecules to release energy. Chloroplasts convert light energy into chemical energy.
The cytoskeleton helps maintain cell shape, is involved in the movement of organelles and cells, and resists stress placed on cells.
Chapter Summary – Section 3

49. 2. DNA 3. Plasma membrane 1. Ribosomes 4. Cell wall
A prokaryotic cell does not have internal organelles surrounded by a membrane. Most of a prokaryote’s metabolism takes place in the cytoplasm.
2. DNA
3. Plasma membrane
1. Ribosomes
4. Cell wall
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Chapter Assessment

50. 1. Nucleus 2. Nucleolus 3. Chromosomes 4. Plasma membrane
This eukaryotic cell from an animal has distinct membrane-bound organelles that allow different parts of the cell to perform different functions.
1. Nucleus
2. Nucleolus
3. Chromosomes
4. Plasma membrane
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5. Organelles
Chapter Assessment