1. A View of the Cell Discovery of the Cell Microscopes The Cell Theory
Prokaryotes vs. Eukaryotes
Eukaryotic Cell Structures
Animal vs. Plant Cells

2. What You’ll Learn
You will identify the parts of prokaryotic and eukaryotic cells.
You will identify the structure and function of the plasma membrane.
You will relate the structure of cell parts to their functions.
Cells are the foundation for the development of all life forms. Birth, growth, death, and all life functions begin as cellular functions.

3. Section Objectives:
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.

4. I. The History of the Cell Theory
People thought that diseases were caused by spirits and curses.
Microscopes allowed you to see microorganisms and cells that were once unknown.

5. A. Development of Microscopes
Simple light microscope – one magnifying lens.
Compound light microscopes use a series of lenses to magnify objects in steps.
These microscopes can magnify objects up to 1,500 X.

6. A. Development of Microscopes
Electron microscopes.
Invented in the 1940s.
uses a beam of electrons to magnify structures up to 500,000 X their actual size.

7. Scanning Electron Microscope Images
Leaf Vein X
Kosher Salt X
Cynthia moth antennae 150X
Toilet Paper X
Hypodermic needle 100X
Mascara brush 35X
Staple through paper 35X
Mosquito Head 200X
House Fly Foot 300X
Instead of SEMs, we use compound light microscopes in school.

8. A. Development of Microscopes
Two basic types of electron microscopes:
The scanning electron microscope (SEM) scans the surface of cells to learn their three dimensional shape.
The transmission electron microscope (TEM) allows scientists to study the structures contained within a cell.

9. Hooke’s drawing of cork cells
Robert Hooke
Robert Hooke
Hooke’s drawing of cork cells
Hooke’s microscope

10. B. The Scientists Robert Hooke
Invented 1st compound microscope in 1665.
The compound microscope had very crude lenses that
magnified objects
Looked at cork and called
these “cells”
Cells are the basic building blocks of all living things.

11. B. The Scientists Anton van Leeuwenhoek –
1st person to record looking at water under a simple microscope
1st to look at living cells
Invented over 200 microscopes during the 1700’s

12. Anton von Leewenhoek Anton von Leewenhoek Leeuwenhoek’s microscope
Described algae like this Spirogyra in his journals.

13. Parts of the Microscope

14. 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.

15. 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.

16. 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

17. The answer is A. Most microscopes use at least two convex lenses
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.

18. The Scientists Theodore Schwann
Observed animals and determined that they were composed of cells
Matthias Schleiden
Observed plants and determined that they were composed of cells

19. The Scientists Rudolf Virchow
Proposed that cells reproduce to produce next generation of cells.

20. The cell theory is made up of three main ideas:
C. The Cell Theory
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.

21. Cells are Organized in Animals
Tissues
Organs
Organ Systems
Organism

22. Cells are Organized in Plants
Tissues
Organs
Organ Systems
Organism

23. II. Two Basic Cell Types EUKARYOTIC
“Eu-” means true - Have a true nucleus that contains long strands of DNA
Can be unicellular or multicellular
Have double membrane-bound organelles.
Size = 10 m m
Found in the kingdoms Protist, Fungi, Plant, & Animal
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Cells containing membrane-bound structures are called eukaryotic cells.

24. II. Two Basic Cell Types Organelles
The membrane-bound structures within eukaryotic cells
Each has a specific function that contributes to cell survival.
Separation of organelles into distinct compartments benefits the eukaryotic cells.
The nucleus is the central membrane-bound organelle that manages cellular functions.

25. II. Two Basic Cell Types PROKARYOTIC Unicellular
Do not have a true nucleus only a circular piece of DNA
Do not have organelles (have ribosomes)
Have a cell wall some surrounded by a slimy capsule
Usually move using method of locomotion requiring flagella or cilia
Size = 0.1 μm - 10 μm
Found only in the kingdoms Eubacteria and Archaebacteria
Cells that do not contain internal membrane-bound structures are called prokaryotic cells.
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26. Organelles
Lysosomes
Nucleus
Plasma Membrane
Endoplasmic Reticulum
Mitochondrion

27. Compare & Contrast

28. Compare & Contrast Prokaryote & Eukaryote Cilia & Flagella
Cells & Tissue
Plant Cell & Animal Cell
Membrane & Cell Wall
Mitochondria & Chloroplast

29. Compare & Contrast

30. Cells

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

32. Question
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

33. Section Objectives
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.

34. A. Cellular Boundaries 1. Plasma membrane Structure
made up of lipids and proteins (phospholipid bilayer)
flexible
Function
controls what enters/leaves the cell - selectively permeable membrane
Maintains homeostasis

35. The cell wall cell wall is a fairly rigid structure
located outside the plasma membrane
Plant = cellulose
Fungus = chitin
Bacteria = peptidoglycan
provides additional support and protection.

36. B. Nucleus and cell control
Nucleolus
Chromatin
Nuclear Envelope

37. Nucleus
Structure
large and central organelle surrounded by a nuclear membrane
contains DNA in the form of chromatin
has nucleolus inside
Function:
Control center For all the activities of the cell.
Contains instructions (in the form of DNA) for making proteins

38. C. Assembly, Transport, and Storage
endoplasmic reticulum (ER) Structure network of folded membranes that extend from nucleus suspended in the cytoplasm Function site of cellular chemical reactions; used to transport materials throughout cell.

39. C. Assembly, Transport, and Storage
Ribosomes Structure tiny dark structures found scattered throughout cytoplasm or attached to RER Function site of protein synthesis

40. Endoplasmic Reticulum (ER)
C. Assembly, Transport, and Storage
Endoplasmic Reticulum (ER)
Ribosomes

41. C. Assembly, Transport, and Storage
3. Golgi body Structure organelle that is suspended in the cytoplasm stacks of membrane sacs contain enzymes to modify proteins Function where proteins are packaged and modified for movement around and out of the cell.

42. C. Assembly, Transport, and Storage
Golgi Apparatus

43. Vacuoles and storage 4. Vacuoles Structure - membrane-bound sacs
Animal
Cell
Vacuoles and storage
4. Vacuoles
Structure - membrane-bound sacs
Notice any differences between vacuoles in plant and animal cells?
Function
used for temporary storage of materials like water and carbohydrates.
Vacuole
Plant
Cell

44. D. Lysosomes and recycling
Structure
Membrane sacs that contain digestive enzymes.
Function
digest excess or worn out organelles, food particles, and engulfed viruses or bacteria.

45. Mitochondria and energy
Structure
Outer membrane with highly folded inner membrane
Found in both plant and animal cells
Function
C6H12O6 + O2  CO2 + H2O + ATP
transform glucose into energy for the cell.

46. Chloroplasts and energy
Energy Transformers:
Chloroplasts and energy
Chloroplasts
Structure
Outer membrane with stacks of membranes filled with chlorophyll, the green pigment that gives leaves and stems their color
Function CO2 + H2O  C6H12O6 + O2
capture light energy and produce food to store for a later time.

47. F. Movement through the Cell
Proteins made in the rough ER move to 
Vesicles 
Golgi body sacs 
Lysosome  for digestion
Food vacuole  exit cell OR
Other organelles  cell for use

48. G. Structures for Support and Locomotion
Cells have a support structure called the cytoskeleton within the cytoplasm. The cytoskeleton is composed of:
microtubules - microtubules are thin, hollow cylinders made of protein
Microfilaments - microfilaments are thin solid protein fibers.

49. 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.

50. Cilia and flagella
Cilia
2. Cilia are short, numerous, hair-like projections that move in a wavelike motion.

51. Cilia and flagella
3. Flagella are long projections that move in a whip-like motion. Flagella and cilia are the major means of locomotion in unicellular organisms.
Flagella

53. Question 1 What is the primary function of the cell wall?
A. act as selectively permeable membrane
B. provide support
C. control activity of organelles
D. acquire nutrients from environment

54. The answer is B. The cell wall is an inflexible, porous barrier that provides support but does not select which molecules can enter the cell.

55. Question 2 Describe the control center of a prokaryotic cell.
Plasma membrane
Ribosomes
DNA
Cell wall

56. 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

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

58. 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.

59. 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.

60. The answer is D. The ER is arranged in a series of folded membranes, which, if spread out, would take up tremendous space.

61. 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.

62. 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.

63. 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

64. The answer is C. Mitochondria transform energy for the cell
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.

65. 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

66. 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

67. Chapter Summary – Section 2
Main Ideas Continued
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

68. 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

69. Question 1 Which of the following is a main idea 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

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

71. Question 2 In what type of cell would you find chlorophyll?
A. prokaryote
B. animal
C. plant
D. fungus
Chapter Assessment

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

73. Question 3
Which of these structures packs proteins into membrane-bound structures?
A. B.
C. D.
Chapter Assessment

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

75. Question 4
Cell wall
What is the difference between the cell wall and the plasma membrane?
Inside cell
Outside cell
Plasma membrane
Chapter Assessment

76. 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

77. Question 5
Which of the following organelles is not bound by a membrane?
A. ribosome
B. Golgi apparatus
C. vacuole
D. lysosome
Chapter Assessment

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

79. Question 6 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

80. Question 7
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

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

82. Question 10
Compare the cytoskeleton of a cell to the skeleton of the human body.
Chapter Assessment

83. 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.
Chapter Assessment

84. 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

85. 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