1. Table of Contents Chapter Preview 3.1 Discovering Cells
3.2 Looking Inside Cells
3.3 Chemical Compounds in Cells
3.4 The Cell In Its Environment

2. Chapter Preview Questions
1. In a microscope, an image is focused by
a. the eyepiece lens and the mirror.
b. the objective lens and the mirror.
c. the eyepiece lens and the objective lens.
d. the objective lens and a concave lens.

3. Chapter Preview Questions
1. In a microscope, an image is focused by
a. the eyepiece lens and the mirror.
b. the objective lens and the mirror.
c. the eyepiece lens and the objective lens.
d. the objective lens and a concave lens.

4. Chapter Preview Questions
2. An electron microscope uses a beam of electrons
instead of
a. slides.
b. lenses.
c. mirrors.
d. light.

5. Chapter Preview Questions
2. An electron microscope uses a beam of electrons
instead of
a. slides.
b. lenses.
c. mirrors.
d. light.

6. Chapter Preview Questions
3. Cells break down carbohydrates to get ____ for life processes.
a. energy
b. food
c. oxygen.
d. carbon dioxide

7. Chapter Preview Questions
3. Cells break down carbohydrates to get ____ for life processes.
a. energy
b. food
c. oxygen
d. carbon dioxide

8. Chapter Preview Questions
4. Cells in green plants make
a. food and carbon dioxide.
b. water and carbon dioxide.
c. food and oxygen.
d. water and carbon dioxide.

9. Chapter Preview Questions
4. Cells in green plants make
a. food and carbon dioxide.
b. water and carbon dioxide.
c. food and oxygen.
d. water and carbon dioxide.

10. What is the structure of a cell?
You hear that a pinch of soil may contain millions of organisms.
What optical tools would you use to see these organisms and to study their structure?

11. Prefixes chlor- chloroplast green
Meaning
Example Word
chloroplast
A cellular structure that captures energy from sunlight
chlor-
green

12. Prefixes cyto- cytoskeleton cell The framework inside a cell Prefix
Meaning
Example Word
cytoskeleton
The framework inside a cell
cyto-
cell

13. Prefixes multi- multicellular many Having many cells Prefix Meaning
Example Word
multicellular
Having many cells
multi-
many

14. Prefixes uni- unicellular one Having one cell Prefix Meaning
Example Word
unicellular
Having one cell
uni-
one

15. Apply It!
1. A chloroplast is a structure in plant cells. What color do you think a
chloroplast is?
green
2. What clue within the word cytoplasm lets you know that the word has
something to do with cells?
the prefix cyto-

16. End of Chapter Preview

17. Section 1: Discovering Cells
What are cells?
How did the invention of the microscope contribute to knowledge about living things?
What is the cell theory?
How are the cells of multicellular organisms organized?

18. Development of the Cell Theory
The cell theory states the following:
All living things are composed of cells.
Cells are the basic units of structure and function in living things.
All cells are produced from other cells.

19. An Overview of Cells
Key concept: Cells are the basic units of structure and function in living things. Examples of function: obtaining oxygen, getting rid of waste, obtaining food, growing, and more… Cells function similarly in all organisms, they carry out the basic processes of life in similar ways. Cells are so small they are measured in micrometers The invention of the microscope Made it possible to discover and Learn about cells

20. Unicellular and Multicellular
Unicellular, or single-celled, organisms include bacteria, the most numerous organisms on Earth. Multicellular organisms are composed of many cells.
Unicellular
Multicellular

21. Multicellular Organisms
Categorized into:
Tissues
Similar cells that work together for specific function
2) Organs
Made of different tissues that work together
Ie. Brain
3) Organ Systems
-A group of organs that work together to perform a major function
-Ie. Cells, tissues, and organs

22. First Observations of Cells
1590ish invention of the microscope Key concept: The invention of the microscope made it possible for people to discover and learn about cells.
Robert Hooke
one of first people to observe cells
built his own microscope- one of the best of his time
observed cork which looked like small rectangular rooms they called cells

23. First Observations of Cells
Anton van Leeuwenhook
Dutch businessman
Built simple microscopes in his spare time
Looked at drops of lake water, scrapings from teeth and gums, water from rain gutters
Animalcules- means “little animals,” small organisms that moved that he found in things like lake water

24. Development of the Cell Theory
Schleiden- all plants are made of cells Schwann- all animals are made of cells Virchow- new cells are formed only from cells that already exist

25. Cell Theory
An explanation of the relationship between cells and living things
All living things are made of cells.
Cells are the basic units of structure and function
All cells are produced from other cells

26. Unicellular and Multicellular
Unicellular- single celled Multicellular- many cells Key concept: “In multicellular organisms, cells are often organized into tissues, organs, and organ systems. Tissue- a group of singular cells that work together Organs- is made up of different kinds of tissue Organ system- a group of organs wanted to what those

27. Click the SciLinks button for links on the cell theory.
Links on Cell Theory
Click the SciLinks button for links on the cell theory.

28. End of Section: Discovering Cells

29. Section 2: Looking Inside Cells
What role do the cell wall and cell membrane play in the cell?
What is the role of the nucleus in the cell?
What organelles are found in the cytoplasm and what are their functions?
How do cells differ?

30. Plant and Animal Cells

31. Cell Wall
The cell wall is a rigid layer of nonliving material that surrounds the cells of plants & some other organisms.
A plant’s cell wall helps to protect & support the cell.
The cell wall is made of a strong, flexible material called cellulose, & many materials can pass through it.

32. Plant and Animal Cells Activity
Click the Active Art button to open a browser window and access Active Art about plant and animal cells.

33. All cells have cell membranes.
In cells that do not have cell walls, the cell membrane is the outside boundary that separates the cell from its environment. (Barrier-like a window Screen)
All cells have cell membranes.
In cells with cell walls, the cell membrane is located just inside the cell wall.
The cell membrane controls what substances come into & out of a cell. (ie. Food & oxygen)
*In plant cells and animal cells
----- Meeting Notes (10/12/11 12:40) -----

34. Nucleus
The nucleus is the cell’s control center, directing all of the cell’s activities.

35. Nuclear Envelope
The nucleus is surrounded by a protective membrane called the nuclear envelope.
Materials pass in & out of the nucleus through small openings, or pores, in the nuclear envelope.

36. Chromatin Directs the Nucleus
Strands that contain the genetic material, the instructions for directing the the cell’s functions.

37. Cytoplasm
The cytoplasm is the region between the cell membrane & the nucleus.
Many cell organelles are found in the cytoplasm.

38. Mitochondrion
Mitochondria are known as the “powerhouses” of the cell because they convert energy in food molecules to energy the cell can use to carry out its functions.

39. Endoplasmic Reticulum
The endoplasmic reticulum is similar to the system of hallways in a building. Proteins and other materials move throughout the cell by way of the endoplasmic reticulum. The spots on this organelle are ribosomes, which produce proteins.

40. Endoplasmic Reticulum
Passageways called the endoplasmic reticulum carry proteins & other materials from one part of the cell to another.

41. Ribosomes
Small, grainlike bodies called ribosomes function as factories to produce proteins.
In plant and animal cells.

42. Golgi Body
The Golgi bodies receive proteins and other newly formed materials from the endoplasmic reticulum, package them, and distribute them to other parts of the cell.

43. Chloroplasts
The Golgi Bodies release materials outside the cell.
In plants, & some other organisms, large, green structures called chloroplasts capture energy from sunlight & use it to produce food for the cell.

44. Vacuoles
Large water-filled sacs called vacuoles are the storage areas of cells.
A vacuole stores food & other materials needed by the cell.

45. Lysosomes
Small, round structures called lysosomes contain chemicals that break down certain materials in the cell.

46. Organelles
Inside a cell are tiny structures called organelles, which carry out specific functions within the cell.
The nucleus is a large, oval structure that acts as the “brain” of the cell.
You can think of the nucleus as the cell’s control center, directing all of the cell’s activities.

47. The Cytoplasm and Organelles
Click the Video button to watch a movie about cytoplasm and organelles.

48. Bacterial Cells
Bacterial cells are smaller & different from plant & animal cells.
While a bacterial cell does have a cell wall & a cell membrane, it does not contain a nucleus.
The bacterial cell’s genetic material, which looks like thick, tangles string, is found in the cytoplasm.
Bacterial cells contain ribosomes, but none of the other organelles found in plant & animal cells

49. Cell Diversity
The Variety is cell structure in cells reflects differences in cell function.
A cells structure is complementary to it’s function
Example- Red blood cell shape to fit through tiny vessels

50. End of Section: Looking Inside Cells

51. Section 3: Chemical Compounds in Cells
What are elements and compounds?
How is water important to the function of cells?
What are the functions of carbohydrates, lipids, proteins, and nucleic acids?

52. An element is a pure substance where all the atoms in a sample of matter have the same identity, and cannot be broken down into simpler substances. For example all of the elements in the periodic table.
Compounds are made from atoms of two or more elements that are combined chemically. Smallest unit of a compound is a molecule.

53. Elements and Compounds
Carbon dioxide, which is found in gas bubbles, is a chemical compound. So is water.

54. Most chemical reactions that take place within cells could not take place without water.
Has to have Carbon to be organic
Many compounds in living things contain the element carbon, Compounds that do not contain carbon are called inorganic compounds. Water and sodium chloride are familiar examples of inorganic compounds.

55. Compounds in Bacteria and Mammals
All cells contain carbohydrates, lipids, proteins, and nucleic acids, as well as water and other inorganic compounds. But do all cells contain the same percentages of these compounds? The graph compares the percentage of some compounds found in a bacterial cell and a cell from a mammal.

56. Compounds in Bacteria and Mammals
Reading Graphs:
What do the red bars represent? What do the blue bars represent?
Red bars represent percentages of compounds in bacterial cells; blue bars represent percentages of compounds in mammalian cells.

57. Compounds in Bacteria and Mammals
Interpreting Data:
What percentage of a mammalian cell is made up of water? How does this compare to the percentage of water in a bacterial cell?
About 70%; the percentages are the same.

58. Compounds in Bacteria and Mammals
Interpreting Data:
Which kind of compound–proteins or nucleic acids–makes up the larger percentage of a mammalian cell?
Proteins

59. Compounds in Bacteria and Mammals
Drawing Conclusions:
In general, how do a bacterial cell and mammalian cell compare in their chemical composition?
They are similar, though mammalian cells have a lower percentage of nucleic acids, and bacterial cells have a lower percentage of lipids and fewer proteins.

60. Carbohydrates, Lipids & Energy
Carbohydrate- energy-rich organic compound made up of carbon, hydrogen, and oxygen. -Provide energy for the cell - components for cell parts (cellulose-plants) Lipids- energy-rich organic compounds made up of carbon, hydrogen, and oxygen - Provide energy to the cells - make up most of the cell membrane

61. Proteins
Proteins- Large organic molecules made up of carbon, hydrogen, oxygen, nitrogen, and, in some cases, sulfur. Foods- Meat, eggs, fish, nuts, beans Made up of amino acids (20 but many due to combinations) Enzyme- A type of protein that speeds up a chemical reaction in living things.

62. Click the SciLinks button for links on proteins.

63. Nucleic Acids
Very long organic molecules made up of carbon, oxygen, hydrogen, nitrogen, and phosphorus. Contain the instructions that cells need to carry out all functions of life. Types: DNA- genetic material that carries info. About an organism and is passed from parent to offspring - Found in chromatin in the nucleus RNA- role in production of proteins - Found in the cytoplasm as well as the nucleus

64. End of Section: Chemical Compounds in Cells

65. Section 4: The Cell in Its Environment
How do most small molecules cross the cell membrane?
Why is osmosis important to cells?
What is the difference between passive and active transport?

66. A Selective Barrier
The cell membrane protects the contents of the cell and helps control the materials that enter and leave.

67. The Cell in its Environment
1. Selective Permeability – This means that some substances are allowed into a cell and others are not. Permeable means to “pass through”.

68. Diffusion
In diffusion, molecules move from an area of higher concentration to an area of lower concentration.

69. Ratios
The concentration of a solution can be expressed as a ratio. A ratio compares two numbers. It tells you how much you have of one item in comparison to another. For example, suppose you dissolve 5 g of sugar in 1 L of water. You can express the concentration of the solution in ratio form as 5 g:1 L, or 5 g/L.
Practice Problem
Suppose you dissolve 7 g of salt in 1 L of water. Express the concentration of the solution as a ratio.
7 g:1 L or 7 g/L

70. Osmosis
In osmosis, water diffuses through a selectively permeable membrane. (Movement of water by diffusion)

71. Passive and Active Transport
Passive and active transport are two processes by which materials pass through the cell membrane. Active transport requires the cell to use its own energy, while passive transport does not.

72. The Cell in its Environment
2. Two ways substances move in and out of cells – Passive and Active Transport

73. The Cell in its Environment
3. Passive Transport – Movement of material through a cell membrane where energy is not required
a. Diffusion – the movement of molecules from an area of higher concentration to an area of lower concentration. Example: pond water organisms survive because oxygen in the pond water is at higher levels than inside the organism

74. More on Cellular Transport
Click the PHSchool.com button for an activity about cellular transport.

75. End of Section: The Cell in Its Environment

76. QuickTake Quiz
Click to start quiz.