1. Table of Contents Discovering Cells Looking Inside Cells
Chemical Compounds in Cells
The Cell in Its Environment

2. *A cell is the basic unit of life. *All life activities
What is a Cell?
*A cell is the basic
unit of life.
*All life activities
take place inside
cells.

3. *Robert Hooke—first man to see cells (1663)
Discovery of Cells
*Robert Hooke—first man to see cells (1663)
-looked at thin slices of cork
-saw empty boxes and called them cells
-never realized that cells are living things

4. *Anton van Leeuwwenhoek
-father of microbiology
(1600’s)
-improved and developed
many types of microscopes
-discovered microscopic, one
celled organisms and called
them “animalcules”,
meaning “little animals”.

5. *Matthias Schleiden (1838)
-stated all plants are
made of cells
*Theodor Schwann (1839)
-stated all animals are

6. *Rudolph Virchow (1855)
-stated all cells come
from other cells.
*The work of these men
led to the “Cell Theory”

7. The cell theory states: 1. All living things are made of cells.
- Discovering Cells
The cell theory states:
1. All living things are
made of cells.
2. Cells are the basic units of
structure and function in
living things.
3. All cells come from other
cells.

8. Sequencing - Discovering Cells
Construct a flowchart showing how the work of Hooke, Leeuwenhoek, Schleiden, Schwann, and Virchow contributed to scientific understanding of cells.
Discovering Cells
Hooke sees cells in cork.
Leeuwenhoek sees many one-celled organisms.
Schleiden concludes that all plants are made of cells.
Schwann concludes that all animals (and all living things) are made of cells.
Virchow proposes that new cells form only from cells that already exist.

9. Click the SciLinks button for links on the cell theory.
- Discovering Cells
Links on Cell Theory
Click the SciLinks button for links on the cell theory.

10. End of Section: Discovering Cells

11. Eukaryotic vs. Prokaryotic
*All cells are either eukaryotic or prokaryotic.
-Eukaryotic cells —complex cells with a nucleus. All animal and plant cells are eukaryotic.
-Prokaryotic cells—simple cells without a nucleus. All bacteria and cyanobacteria (blue-green bacteria) are prokaryotic.

12. *Cell Membrane -Surrounds the cell -Has pores -Controls what gets
Structure of Animal Cells Animal cells are typical eukaryotic cells. Most contain the following structures:
*Cell Membrane
-Surrounds the cell
-Has pores
-Controls what gets
in and out

13. -directs all of the cell’s activities
- Looking Inside Cells
*Nucleus—control center of cell
-directs all of the cell’s activities
Chromatin
Pores
Nucleolus
Nuclear Envelope

14. *Cytoplasm—gel-like material inside the cell.
*Organelles—many tiny structures inside the cell. Each has its own job to do.
-Organelles include:

15. - Looking Inside Cells
Mitochondria—“powerhouses” of the cell because they convert energy in food molecules to energy the cell can use to carry out its functions.

16. 2. Endoplasmic reticulum —folded tube
- Looking Inside Cells
2. Endoplasmic reticulum —folded tube
like membranes that move materials
throughout the cell.
3. Ribosomes—small protein factories
found on the “er” or in the cytoplasm
Ribosomes
Endoplasmic
reticulum

17. that wrap up and package proteins and send them to other parts of the
- Looking Inside Cells
4. Golgi bodies —packaging centers
that wrap up and package proteins
and send them to other parts of the
cell or out of the cell.
Golgi Body

18. collectors that contain enzymes used to break down
5. Lysosomes—garbage
collectors that contain
enzymes used to break down
large molecules and old cell
parts.

19. dissolved material or waste products.
6. Vacuoles—sacs that store water,
dissolved material or waste products.
They are larger in plant cells than in
animal cells.

20. Structure of Plant Cells
*Plant cells contain all the same structures and organelles as animal cells plus a few more.
Plant cells can do
everything that animal
cells can do plus
make food.

21. -Cell wall—a ridged structure outside the cell membrane made of cellulose. It supports and protects the plant cell.
-Chloroplasts—tiny disks that contain chlorophyll. Photosynthesis takes place here.
-Larger Vacuoles—to store water

22. - Looking Inside Cells
Plant and Animal Cells

23. *Cells differ in size, shape, and
Cell Variety
*Cells differ in size, shape, and
function. They will not all look like the
diagrams.

24. *Examples:
-Nerve cell—0ne meter long with many extensions: carries impulses to the brain.
-Red Blood Cell—microscopic, round and flexible: carries oxygen throughout the body.

25. Structure of Bacteria Cells
*Bacteria cells have no nucleus and no membrane-bound organelles.
-They are prokaryotic.
-Their parts include:
Capsule
Cell wall
Cell membrane
Cytoplasm
DNA floating in cytoplasm
Ribosomes
Some have flagella

26. Diagram of a Bacteria Cell
Cytoplasm
DNA
Capsule
Cell wall
Cell Membrane
Ribosomes
Flagella

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

28. Previewing Visuals - Looking Inside Cells
Before you read, preview Figure 12. Then write two questions you have about the illustrations in a graphic organizer like the one below. As you read, answer your questions.
Plant and Animal Cells
Q. How are animal cells different from plant cells?
A. Plants cells have a cell wall and chloroplasts, which animal cells to not have.
Q. What do mitochondria do?
A. Mitochondria convert energy in food molecules to energy the cell can use.

29. The Cytoplasm and Organelles
- Looking Inside Cells
The Cytoplasm and Organelles
Click the Video button to watch a movie about cytoplasm and organelles.

30. Click the Video button to watch a movie about specialized cells.
- Looking Inside Cells
Specialized Cells
Click the Video button to watch a movie about specialized cells.

31. End of Section: Looking Inside Cells

32. *Cell Chemistry begins with atoms: -Atom—basic units of matter
What are Cells Made Of?
*Cell Chemistry begins with atoms:
-Atom—basic units of matter
-Elements—any substance that
cannot be broken down into
simpler substances (made of
only one type of atom)

33. the Periodic Table of the Elements
-All known elements are listed on
the Periodic Table of the Elements

34. -The elements found in living cells
include mostly carbon, hydrogen,
nitrogen, oxygen, phosphorus
and sulfur: (CHNOPS)

35. Molecules and Compounds
*Atoms combine to form molecules.
-Molecules—two or more atoms
bonded together (different or
same) Ex: H2O O2 NaCl
-Special molecules made of different
elements only are called
compounds Ex: H2O CO2

36. - Chemical Compounds in Cells
Carbon dioxide, which is found in gas bubbles, is a chemical compound. So is water.

37. -When just the right molecules and
compounds get together in just
the right way, cells are formed.
-Compounds in living organisms
are classified as either organic or
inorganic.

38. *Organic compounds contain the
elements; carbon and hydrogen.
*They make up foods and cell membranes.
*Four basic groups:

39. Carbohydrates—make up 1% of a cell; contain carbon, hydrogen, and oxygen; used for energy; examples are sugars and starches; most important carbohydrate for living things is glucose.

40. 2. Lipids—make up 10% of a cell;
contain carbon, hydrogen and
oxygen; store and release
energy; found in cell membranes;
examples are fats, oils and waxes.

41. 3. Proteins—make up 15% of a cell;
made of amino acids that contain
carbon, hydrogen, oxygen and
nitrogen; used to build cell parts
and for growth and repair of cell;
examples are enzymes.

42. 4. Nucleic Acids—make up 4% of a
cell; contain carbon, hydrogen,
oxygen, nitrogen, and phosphorus;
carry genetic information; found
in chromosomes, mitochondria,
chloroplasts, and nucleus;
examples are DNA and RNA

43. Compounds in Bacteria and Mammals
- Chemical Compounds in Cells
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.

44. Compounds in Bacteria and Mammals
- Chemical Compounds in Cells
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.

45. Compounds in Bacteria and Mammals
- Chemical Compounds in Cells
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.

46. Compounds in Bacteria and Mammals
- Chemical Compounds in Cells
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

47. Compounds in Bacteria and Mammals
- Chemical Compounds in Cells
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.

48. *Most inorganic compounds are made from elements other than carbon.
- Chemical Compounds in Cells
*Most inorganic compounds
are made from elements
other than carbon.
Example: Water
-water makes up two-thirds
of your body
-70% of a cell’s cytoplasm
is water
-many substances must
be dissolved in water in
order to be used by cells.

49. Comparing and Contrasting
- Chemical Compounds in Cells
Comparing and Contrasting
As you read, compare and contrast carbohydrates, proteins, and lipids in a table like the one below.
Type of Compound
Elements
Functions
Store and provide energy and make up cellular parts
Carbohydrate
Carbon, hydrogen, oxygen
Make up much of the structure of cells and speed up chemical reactions
Protein
Carbon, hydrogen, oxygen, nitrogen, and sometimes sulfur
Lipid
Carbon, hydrogen, oxygen
Store energy

50. Click the SciLinks button for links on proteins.
- Chemical Compounds in Cells
Links on Proteins
Click the SciLinks button for links on proteins.

51. End of Section: Chemical Compounds in Cells

52. *The cell membrane controls what gets in and out of the cell. This is
Cell Transport
*The cell membrane controls what
gets in and out of the cell. This is
called Cell Transport.
-Substances pass through pores.
-The membrane is
selectively-permeable (meaning only molecules of a certain size can get through).

53. A Selective Barrier - The Cell in Its Environment
The cell membrane protects the contents of the cell and helps control the materials that enter and leave.

54. *Passive Transport —cell uses no energy to move materials into or out
Types of Transport
*Passive Transport —cell uses
no energy to move materials into or out
of the cell.
-Two types of Passive Transport:
1. Diffusion
2. Osmosis

55. *Diffusion is a type of passive transport in which molecules move from high to low concentration.
Oxygen and carbon dioxide move
into a cell by diffusion.
-Molecules move through tiny pores in
the cell membrane.
-Diffusion requires no energy from the
cell.

57. Diffusion - The Cell in Its Environment
In diffusion, molecules move from an area of higher concentration to an area of lower concentration.

58. Ratios - The Cell in Its Environment
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

59. *Osmosis is a type of passive
transport in which water moves
from high to low concentration.
-Plants get water into their roots
by osmosis.
-Osmosis also requires no energy
from the cell.

61. Osmosis - The Cell in Its Environment
In osmosis, water diffuses through a selectively permeable membrane.

62. Equilibrium
*Both diffusion and osmosis will continue until the cell reaches a point where the concentrations are equal both inside and outside the cell. This is called equilibrium.

63. *Active Transport —cell must
use energy to move substances
in or out.
-Cell will move things from low to
high concentration.
-Transport proteins are needed.

64. Passive and Active Transport
- The Cell in Its Environment
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.

65. Endocytosis—process used by cells to move very large substances into the cell.

66. Exocytosis —process used by cells to move very large substances out of the cell.

68. Building Vocabulary - The Cell in Its Environment
A definition states the meaning of a word or phrase. After you read the section, reread the paragraphs that contain definitions of Key Terms. Use all the information you have learned to write a definition of each Key Term in your own words.
Key Terms:
Key Terms:
Examples:
passive transport
active transport
Examples:
selectively permeable
The movement of dissolved materials through a cell membrane without using cellular energy is called passive transport.
The cell membrane is selectively permeable, which means that some substances can pass through the membrane while others cannot.
diffusion
Diffusion is the process by which molecules move from an area of higher concentration to an area of lower concentration.
Active transport is the movement of materials through a cell membrane using cellular energy.
osmosis
Osmosis is the diffusion of water molecules through a selectively permeable membrane.

69. More on Cellular Transport
- The Cell in Its Environment
More on Cellular Transport
Click the PHSchool.com button for an activity about cellular transport.

70. End of Section: The Cell in Its Environment

71. Graphic Organizer Organic Compounds Carbo-hydrates Nucleic acids
types
made of
include
Organic Compounds
Carbo-hydrates
Nucleic acids
Lipids
Proteins
Fats, oils, and waxes
Amino acids
Sugars
Starches
DNA
RNA

72. End of Section: Graphic Organizer