1. The Life of a Cell The Discovery of Cells
Unit Overview – pages

2. Cells : the basic building blocks of all living things.

3. 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.
Observed single celled organisms in the water
Section 7.1 Summary – pages

4. Simple Light Microscope

5. 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 1,500 times.
Section 7.1 Summary – pages

6. Section 7.1 Summary – pages 171-174
The Cell Theory
Robert Hooke was an English scientist who lived at the same time as van Leeuwenhoek.
Hooke used a compound light microscope to study cork, the dead cells of oak bark.
Section 7.1 Summary – pages

7. Compound Light Microscope

8. The Cell Theory
Matthais Schleiden (1838)
Observed plants- and concluded that all plants are made of cells.
Theodor Schwann (1939)
Observed animals and concluded that all animals are made of cells.

9. The Cell Theory
Rudolf Virchow
Concluded that the nucleus was responsible for cell division

10. 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

11. 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 500,000 times their actual size.
Section 7.1 Summary – pages

12. 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

13. Section 7.1 Summary – pages 171-174
Two Basic Cell Types
1. Prokaryotic cells : Cells that do not contain internal membrane-bound structures
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

14. Section 7.1 Summary – pages 171-174
Two Basic Cell Types
2. Eukaryotic cells:
Cells containing membrane-bound structures
Most of the multi-cellular plants and animals
Section 7.1 Summary – pages

15. Section 7.1 Summary – pages 171-174
Organelles: the membrane-bound structures within eukaryotic cells
Each organelle has a specific function that contributes to cell survival.
Section 7.1 Summary – pages

16. Question 1
How did the invention of the microscope impact society’s understanding of disease?
A. Scientists were able to view microorganisms that were previously unknown.
B. Microscopes were invented after the development of the cell theory.
C. It was once believed that viruses, not bacteria, caused diseases.
D. Scientists could view membrane-bound organelles of prokaryotes.
Section 1 Check

17. 1) The answer is A. Before microscopes were invented, people believed that curses and supernatural spirits caused diseases. Microscopes enabled scientists to view cells, which led to the discovery that microorganisms cause some diseases.
Section 1 Check

18. Question 2
Which of the following uses a beam of light and a series of lenses to magnify objects in steps?
A. compound light microscope
B. scanning electron microscope
C. transmission electron microscope
D. simple light microscope
Section 1 Check

19. 2) The answer is A. Most microscopes use at least two convex lenses
2) The answer is A. Most microscopes use at least two convex lenses. Compound light microscopes use a light beam and a series of lenses and can magnify objects up to about 1500 times. Electron microscopes use a beam of electrons and can magnify structures up to times.
Section 1 Check

20. Question 3 What makes this cell eukaryotic?
A. Because it has a cell wall.
Nucleus
Nucleolus
B. Because it contains DNA.
C. Because it has membrane-bound organelles.
D. Because it does not have DNA.
Chromosomes
Organelles
Plasma membrane
Section 1 Check

21. 3) The Answer is C. Eukaryotic cells contain membrane-bound organelles that have specific functions in the cell; prokaryotic cells do not.
Nucleus
Nucleolus
Chromosomes
Organelles
Plasma membrane
Section 1 Check

22. Question 4 What are the components of the cell theory?
A. All organisms are composed of one cell.
B. The organelle is the basic unit structure and organization of organisms.
C. All cells come from two parent cells.
D. All cells come from preexisting cells.
Chapter Assessment

23. 4) The answer is D. The cell theory states that a cell divides to form two identical cells.
Chapter Assessment

24. Prokaryotic
Eukaryotic
3 Facts
3 Facts
2 Similarities

25. 1. What is happening to the starch and the sugar. 2
1.What is happening to the starch and the sugar? 2. What does this tell you about the membrane covering the test tube?

26. The Life of a Cell
The Plasma Membrane
Unit Overview – pages

27. 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.
What is this called?
Summary Section 2 – pages

28. Summary Section 2 – pages 175-178
Why cells must control materials
What helps cells control homeostasis?
Plasma membrane :the boundary between the cell and its environment.
Selective permeability : a process used to maintain homeostasis allowing some molecules into the cell while keeping others out.
Summary Section 2 – pages

29. 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

30. Plasma Membrane
Water

31. 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 : lipids with a phosphate attached to them.
Summary Section 2 – pages

32. 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

33. Summary Section 2 – pages 175-178
Makeup of the phospholipid bilayer
The phosphate heads are polar and hydrophilic. They face out.
The fatty acid tails are nonpolar and hydrophobic. They face inside
Summary Section 2 – pages

34. Summary Section 2 – pages 175-178
Makeup of the phospholipid bilayer
Fluid mosaic model : the phospholipids move within the membrane (waves), as well as, the proteins in the membrane (boats).
Summary Section 2 – pages

35. Summary Section 2 – pages 175-178
Components of the plasma membrane:
Cholesterol prevents the fatty acid chains of the phospholipids from sticking together.
Cholesterol
Molecule
**Think spaghetti and olive oil**
Summary Section 2 – pages

36. Summary Section 2 – pages 175-178
Components of the plasma membrane:
Transport proteins: move needed substances or waste materials through the plasma membrane.
Other proteins and carbohydrates stick out of the cell’s surface to identify chemical signals.
Summary Section 2 – pages

38. Question 1
Which of the following best describes the plasma membrane’s mechanism in maintaining homeostasis?
A. protein synthesis
B. selective permeability
C. fluid composition
Section 2 Check

39. Question 2 Describe the structure of the plasma membrane.
Section 2 Check

40. 2) The plasma membrane is composed of a phospholipid bilayer, which has two layers of phospholipids back-to-back. The polar heads of phospholipid molecules contain phosphate groups and face outward.
Section 2 Check

41. Question 3
Phospholipid molecule
Why is the phosphate group of a phospholipid important to the plasma membrane?
Polar head (includes phosphate group)
Nonpolar tails (fatty acids)
Section 2 Check

42. 3) When phospholipid molecules form a bilayer, the phosphate groups lie to the outside. Because phosphate groups are polar, they allow the cell membrane to interact with its watery (polar) environments inside and outside the cell.
Phospholipid molecule
Polar head (includes phosphate group)
Nonpolar tails (fatty acids)
Section 2 Check

43. Question 4
Explain why the model of the plasma membrane is called the fluid mosaic model.
Section 2 Check

44. 4) It is fluid because the phospholipid molecules move within the membrane. Proteins in the membrane that move among the phospholipids create the mosaic pattern.
Section 2 Check

45. Question 5
__________ span the entire plasma membrane and regulate which molecules enter and leave the cell.
A. Transport proteins
B. Cholesterol molecules
C. Ribosomes
D. Microtubules
Chapter Assessment

46. 5) The answer is A. Transport proteins form the selectively permeable membrane and move needed substances or waste materials through the plasma membrane.
Chapter Assessment

47. Question 6 What is the role of cholesterol in the plasma membrane ?

48. 6) The answer is B. Selective permeability is the process in which the membrane allows some molecules to pass through, while keeping others out.
Section 2 Check

49. 6) Cholesterol helps to stabilize the phospholipids in the plasma membrane by preventing their fatty acid tails from sticking together.
Phospholipid molecules
Cholesterol molecule
Chapter Assessment

50. 1. What do plants and animals need to stay alive. 2
1. What do plants and animals need to stay alive? 2. Name some ways plant and animal cells would be similar. Name some differences. Why do you think that?

51. The Life of a Cell
The Eukaryotic Cell
Unit Overview – pages

52. Section 3 Summary – page 179-187
Cellular Boundaries
The plasma membrane acts as a selectively permeable membrane.
Cell wall : rigid structure located outside the plasma membrane that provides additional support and protection.
Section 3 Summary – page

53. Section 3 Summary – page 179-187
Nucleus and cell control
Nucleolus: helps with ribosome production
Chromatin : are strands of genetic material
Nuclear Envelope
Section 3 Summary – page

54. Inside the Eukaryotic Cell
Cytoplasm: the gelatin-like material inside every cell; it constantly flows inside the cell

55. Section 3 Summary – page 179-187
Assembly, Transport, and Storage
Endoplasmic reticulum (ER) : the site of cellular chemical reactions; products are transported through tubules that make up the ER
Section 3 Summary – page

56. Section 3 Summary – page 179-187
Assembly, Transport, and Storage
Endoplasmic Reticulum (ER)
Ribosomes : the smallest organelles that are not membrane bound and make proteins
Section 3 Summary – page

57. Section 3 Summary – page 179-187
Assembly, Transport, and Storage
Golgi Apparatus stacked, flattened membranes used to sort cellular substances and package them into membrane bound structures called vesicles
Section 3 Summary – page

58. Assembly, Transport, and Storage
What is the advantage of highly folded membranes in cells?
A large amount of work can be done in a small space

59. Section 3 Summary – page 179-187
Vacuoles and Storage
Vacuoles : spaces used for temporary storage of materials.
*Notice the difference between vacuoles in plant and animal cells.
Vacuole
Animal
Cell
Plant
Cell
Section 3 Summary – page

60. Lysosomes and Recycling
Lysosomes : organelles that contain digestive enzymes.
Digest excess or worn out organelles, food particles, and engulfed viruses or bacteria.

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

62. 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

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

64. Section 3 Summary – page 179-187
Structures for Support and Locomotion
Cytoskeleton : support structure composed of microtubules and microfilaments.
Section 3 Summary – page

65. 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

66. Section 3 Summary – page 179-187
Cilia and flagella: used for locomotion
Cilia
Cilia : short, numerous, hair-like projections that move in a wavelike motion.
Section 3 Summary – page

67. Section 3 Summary – page 179-187
Cilia and Flagella
Flagella : 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

68. To return to the chapter summary click escape or close this document.
Fold one sheet of paper lengthwise.
To return to the chapter summary click escape or close this document.

69. To return to the chapter summary click escape or close this document.
Fold into thirds.
To return to the chapter summary click escape or close this document.

70. To return to the chapter summary click escape or close this document.
Unfold and draw overlapping ovals. Cut the top sheet along the folds.
To return to the chapter summary click escape or close this document.

71. To return to the chapter summary click escape or close this document.
Label the ovals.
To return to the chapter summary click escape or close this document.

72. K W L 1. 2. 3. 1. 2. 3. Write 3 things that you’ve learned about
3 things you already
know about cells
3 things you want to know about cells K W L 1. 2. 3. 1. 2. 3.
Write 3 things
that you’ve
learned about
Cells so far

73. Review 1a. What type of cells have cell walls?
1b. What is the primary function of the cell wall?
Section 3 Check

74. ANSWER:
The cell wall is an inflexible, porous barrier that provides support but does not select which molecules can enter the cell.
Section 3 Check

75. Question 2 Describe the control center of a prokaryotic cell.
Plasma membrane
Ribosomes
DNA
Cell wall
Section 3 Check

76. 2) Prokaryotic cells do not have true nuclei; their DNA is not separated from the rest of the cell by a membrane.
Plasma membrane
Ribosomes
DNA
Cell wall
Section 3 Check

77. Question 3
Which of the following structures is the site of protein synthesis?
A. Golgi apparatus
B. Ribosome
C. Vacuole
D. Lysosome
Section 3 Check

78. 3) The answer is B. Ribosomes are the sites where the cell produces proteins according to the directions of DNA. They can be attached to the surface of the endoplasmic reticulum or float freely in the cytoplasm.
Section 3 Check

79. Question 4 What is the advantage of having numerous folds in the ER?
A. It enables the ER to lie snugly against the nucleolus.
B. It can create more vesicles in a smaller space.
C. It can capture more light energy with more folds.
D. A large amount of work can be done in a small space.
Section 3 Check

80. 4) The answer is D. The ER is arranged in a series of folded membranes, which, if spread out, would take up tremendous space.
Section 3 Check

81. Question 5
What could you predict about a plant cell that contains fewer chloroplasts than other plant cells?
A. It contains less chlorophyll.
B. It contains a greater number of plastids.
C. It will have an increased rate of light energy capture.
D. It will appear darker green in color.
Section 3 Check

82. 5) The answer is A. Chloroplasts are among the plant organelles known as plastids and contain the green pigment chlorophyll. Chlorophyll traps light energy from the Sun and gives leaves and stems their green color.
Section 3 Check

83. Question 6
A mutation results in the inner membranes of a liver cell’s mitochondria being smooth, rather than folded. Which of the following would you expect?
A. more efficient storage of cellular energy
B. it can create more vesicles in a smaller space
C. decreased energy available to the cell
D. fewer ribosomes available for protein synthesis
Section 3 Check

84. 6) The answer is C. Mitochondria transform energy for the cell
6) The answer is C. Mitochondria transform energy for the cell. A highly folded inner membrane provides a greater surface area for producing energy-storing molecules.
Section 3 Check

85. Question 7 In what type of cell would you find chlorophyll?
A. prokaryote
B. animal
C. plant
D. fungus
Chapter Assessment

86. 7) The answer is C. Chlorophyll is the green pigment found in the chloroplasts of plant cells.
Chapter Assessment

87. Question 8
Which of these structures packs and sorts proteins into membrane-bound structures?
A. B.
C. D.
Chapter Assessment

88. Answer C depicts the Golgi apparatus, which sorts proteins and packs them into vesicles.
Chapter Assessment

89. Question 9
Cell wall
What is the difference between the cell wall and the plasma membrane?
Inside cell
Outside cell
Plasma membrane
Chapter Assessment

90. 9) The plasma membrane is a flexible boundary between the cell and its environment that controls the supply of nutrients, waste, and other products entering and leaving the cell. The cell wall is a rigid structure found in plant cells, fungi, bacteria and some protists that provides support and protection but does not select which molecules can enter or leave the cell.
Cell wall
Inside cell
Outside cell
Plasma membrane
Chapter Assessment

91. Question 10
Which of the following organelles is not bound by a membrane?
A. ribosome
B. Golgi apparatus
C. vacuole
D. lysosome
Chapter Assessment

92. 10) The answer is A. Ribosomes are simple structures made of RNA and protein and are not bound by membranes.
Ribosomes
Chapter Assessment

93. Question 11 In which of the following pairs are the terms related?
A. cell wall – selective permeability
B. prokaryote – mitochondria
C. microfilaments – locomotion
D. plastid – storage
Chapter Assessment

94. 11) The answer is D. Plastids are plant organelles that are used for storage.
Chapter Assessment

95. Question 12
Which of the following structures is found in both plant and animal cells?
A. chloroplast
B. cell wall
C. mitochondrion
D. thylakoid membrane
Chapter Assessment

96. 12) The answer is C. Mitochondria are the organelles in both plant and animal cells that transform energy for the cell.
Chapter Assessment

97. Question 13
Compare the cytoskeleton of a cell to the skeleton of the human body.
Chapter Assessment

98. 13) The cytoskeleton and skeleton are similar in that both form a framework. However, the cytoskeleton is a constantly changing structure with the ability to be disassembled in one place and reassembled in another.