1. Table of Contents
Chemical Compounds in Cells (1.3) The Cell in Its Environment (1.4) Photosynthesis (2.1) Respiration (2.2)

2. 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)

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

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

5. Molecules and Compounds. Atoms combine to form molecules
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

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

7. -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.

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

9. 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.

10. 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.

11. 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.

12. 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

13. 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

14. 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.

15. 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.

16. 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.

17. 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

18. 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.

19. *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.

20. 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

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

22. 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).

23. 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.

24. 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

25. *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.

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

28. 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

29. *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.

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

32. 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.

33. Active Transport —cell must use energy to move substances in or out
*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.

34. 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.

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

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

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

39. 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.

40. 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.

41. 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:

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

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

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

45. -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.

46. -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.

47. 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

48. Cellular Respiration
-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.

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

50. 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.

51. -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.

52. 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.

53. 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.

54. Lactic Acid Fermentation—occurs during very hard exercise
*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.

55. Photosynthesis
CO2
C6H12O6
H2O O2
Sunlight
(Energy)

56. Cellular
Respiration
CO2
C6H12O6
H2O O2
Energy