Review Assignments
1. pH Puzzler
2. Notes: Atoms & Molecules
3. Water is Life
4. Carbon Compounds
5. Lab: Nutrient Testing
6. 3-D Molecules
7. Enzyme Experiment 1

Good Morning! 
Please get a computer, log on, and navigate to
section of class web site…..

Study Hall: Library, Room 214, Room 105

Due today (30 pts)! Test Monday
Covers Chapter 2: pp. 35-53

21. Describe 3 ways life on Earth depends on water.
• Living things made up mainly of water
( ~70%)
• Helps keep temperatures from getting too hot or too cold.
• Helps dissolve substances needed for life: oxygen, carbon dioxide, nutrients.

1. What is the difference between an element and a compound? Give an example of each.
• Compound made of 2 or more elements joined together.
• Elements: oxygen, hydrogen, carbon, nitrogen
• Compounds: water, carbon dioxide, sugar, lipids, proteins.
Water
H
2
O

2. What is the difference between an atom and a molecule?
Give an example of each.
• Molecule made of 2 or more atoms joined together.
• Atoms: hydrogen, oxygen, carbon
• Molecules: water, carbon dioxide, sugar, lipid, protein.
Glucose molecule
C
6
H
12
O
6

3. What three chemical elements are found in all the molecules that make up living things? Which one forms the “backbone” of all of them?
• Carbon, hydrogen, oxygen
• Carbon

4. What are the four main groups of carbon compounds found in all life on Earth?
Carbohydrates, lipids, proteins, nucleic acids

5. What are the two main forms of carbohydrates used by living things? What is their main function? Identify 5 good food sources for carbohydrates.
• Sugars and starches
• Main source of quick energy.
• Starch: bread, cereal, rice, pasta, potato
• Sugar: soda pop, candy, cake

6. How are starch and sugar molecules related?
Starch molecule made of sugar molecules joined together.
Glucose (sugar) starch

7. What is glucose, and why is it important to ALL life on Earth?
• A kind of sugar.
• Main source of energy for
ALL living things.
Glucose = the sugar plants make in photosynthesis

8. What are the two main forms of lipids used by living things? What is their main function?
• Fats and oils
• Store energy
• Also form cell membranes

9. Identify 3 good food sources for lipids.
• Meat, poultry, fish, nuts, dairy, anything fried.

10. Which kind of fats are less healthy for you, saturated or unsaturated? Explain why.
• Saturated.
• Clog arteries. Can lead to high blood pressure, heart attacks.

11. How amino acid and protein molecules related?
Protein molecules made up of amino acid molecules joined together.

12. What are four different functions of proteins in living things?
• Building materials for muscle, skin, bone, etc.
• Speed up chemical reactions (enzymes)
• Control what goes in and our of cells.
• Help fight infections (antibodies)

13. Identify 4 good food sources for proteins.

14. Explain the function of nucleic acids in living things and give an example of one.
• Carry genetic information for traits inherited from parents, e.g. hair color, eye color.
• DNA

15. Why is it important to eat food from all the different food groups, rather than just some of them?
• So your body gets ALL the nutrients it needs.
• Different groups have different nutrients.

16. What are enzymes and why are they important to living things?
• Proteins that speed up chemical reactions.
• Without them, body functions wouldn’t work.

17. How does the shape of an enzyme molecule affect its ability to function?
• Enzymes fit with substrate molecules like locks and keys.
• If you change the shape of the enzyme molecule, it won’t fit with other molecule, won’t work.

18. What is a control group in an experiment? When does an experiment need a control group to be valid?
• Test group used to compare the other test group(s) to.
• When you want to see the effect of something on something else, e.g. effect of acid on enzyme reaction.

19. What should we always do to make our experiment conclusions more reliable?
• Repeat the experiment!

20. What was the manipulated variable in our first enzyme experiment? What was the responding variable?
• Amylase (enzyme)
• Amount of sugar

Questions?