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 H2O

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, nitrogen• Molecules: water, carbon dioxide, sugar, lipid, protein.

Glucose molecule C6H12O6

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?

CarbohydratesLipidsProteinsNucleic 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.

• Bread, cereal, rice, pasta, potato

• Anything with sugar

6. How are starches and sugars related?

• Starch molecule made of sugar molecules joined together.

• Both are carbohydrates, both used for energy.

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

sugar

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 acids and proteins 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.

Meat, fish, poultry, nuts, dairy, dry beans

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, RNA

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.

Questions?