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

2. Review *A cell is the basic unit of life. *All life activities
take place inside
cells.

3. - Discovering Cells
Review
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.

4. 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.

5. Review
Eukaryotic cells —complex cells with a nucleus. All animal, plant, fungi, and protist cells are eukaryotic.
Prokaryotic cells—simple cells without a nucleus. All bacteria and cyanobacteria (blue-green bacteria) are prokaryotic.

6. Review: Cell Parts
Cell Membrane - Surrounds the cell, contains pores and controls what enters and leaves. (Made of a lipid bilayer)
Nucleus—control center of cell, which directs all of the cell’s activities

7. Review: Cell Parts
Cytoplasm—gel-like material inside the cell, which hold organelles in place.
Mitochondria—“powerhouses” of the cell because they convert energy in food molecules to energy the cell can use to carry out its functions.
Endoplasmic reticulum — folded tube
like membranes that move materials
throughout the cell
- Ribosomes—small protein factories
found on the “er” and in the cytoplasm

8. Review: Cell Parts
Golgi bodies —packaging centers that wrap up and package proteins and send them to other parts of the cell or out of the cell.
Lysosomes —garbage collectors that contain enzymes used to break down large molecules and old cell parts.
Vacuoles —sacs that store water, dissolved material or waste products. They are larger in plant cells than in animal cells.

9. Review: Cell Parts (Plants Only)
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 and is where photosynthesis takes place.
Larger Vaculoes —to store water

10. - Looking Inside Cells
Plant and Animal Cells

11. Review: Bacteria cell parts
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

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

13. 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.

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

15. 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.

16. *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)

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

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

19. 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

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

21. -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.

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

23. 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.

24. 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.

25. 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.

26. 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

27. 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

28. 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.

29. 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.

30. 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.

31. 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

32. 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.

33. *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.

34. 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

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

36. *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).

37. 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.

38. *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

39. *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.

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

42. 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

43. *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.

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

46. 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.

47. *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.

48. 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.

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

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

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

53. Energy in Living Things
-Every living thing needs energy.
-The cells of living things need
energy too.
-The sun is the direct or indirect
source of energy for most
living things.

54. The sun is the indirect source of energy. The sun is the direct
- Photosynthesis
The sun is the indirect
source of energy.
The sun is
the direct
source of
energy.
The sun is
the source
of energy for
most living
things
The zebra gets
energy from
eating grass.
The lion gets energy
by feeding on the
zebra.
Plants use energy
from the sun to
make food.

55. Photosynthesis
-Photosynthesis is the process by which
a cell captures energy in sunlight and
uses it to make food.
-Autotrophs —organisms that make
their own food. Examples: Plants, some
protists, some bacteria.
-Two stages of photosynthesis:

56. *Stage 1: Chlorophyll captures the energy from sunlight.
- Photosynthesis
*Stage 1: Chlorophyll captures the
energy from sunlight.

57. *Stage 2: The captured light energy is used to produce sugar and oxygen from carbon dioxide and water.

58. -Water (H2O) enters the plant through
the roots and travels to the leaves.
-Carbon Dioxide (CO2) enters the
plant through stomata in the leaves.

59. -In the chloroplasts, water and carbon
dioxide undergo several chemical
reactions powered by the light energy.
-The products are glucose and oxygen.
-Glucose is used for food or stored in
other forms to be used later.

60. -Some of the oxygen is used to
break down the glucose molecules and
release energy.
-The rest is released to the atmosphere
through the stomata.

61. The Photosynthesis Equation
-Chemists use equations to summarize
chemical reactions.
-The equation for photosynthesis is:
light
energy
6CO H2O C6H12O O2
Carbon Water Glucose Oxygen
dioxide

62. -Cellular Respiration is the process by
which cells obtain energy from glucose.
-The chemical bonds of the glucose
molecule are broken to release energy.
-All cells carry out respiration
continuously.
-Respiration happens in the
mitochondria.

63. The Respiration Equation
-The equation for respiration is:
C6H12O O CO H2O + energy
Glucose Oxygen Carbon Water
dioxide

64. Comparing Photosynthesis and Respiration
-Photosynthesis and respiration can be
thought of as opposite processes.
-During photosynthesis, plants use
carbon dioxide and release oxygen.
-During respiration, organisms use
oxygen and release carbon dioxide.

65. -This keeps the levels of both gases constant in Earth’s atmosphere.
- Respiration
-This keeps the levels of both gases
constant in Earth’s atmosphere.

66. Fermentation
-Fermentation provides energy for
cells without using oxygen.
*The amount of energy released
from each sugar molecule is
much less than the amount
released during respiration.

67. Types of Frementation
-Two types of Fermentation:
*Alcoholic Fermentation—occurs
when yeast break down sugars.
Alcohol, carbon dioxide and a
small amount of energy are the
products. Yeast is used by
bakers and brewers.

68. *Lactic Acid Fermentation—occurs
during very hard exercise. Muscles
use oxygen faster than you can
replace it so fermentation begins to
supply additional energy.
Lactic acid is produced and causes
sharp pains.