Water & Macromolecules Quiz

1. The image below shows a model of a water molecule. The center, red portion represents

• an atom of hydrogen that has a positive charge.
• an atom of oxygen that has a positive charge.
• an atom of oxygen that has a negative charge.

2. Which of the following best explains why a molecule of water is polar?

• A molecule of water has two hydrogen atoms and one oxygen atom.
• The electrons in the molecule are pulled toward the oxygen and away from the hydrogens. This results in a slightly negative charge on the oxygen side and a slightly positive charge on the hydrogen side.
• There is not an equal number of oxygen atoms to hydrogen atoms. This makes the charges on the molecule uneven.

3. Which property of water helps to maintain a constant, stable temperature on Earth?

• capillary action
• high specific heat
• surface tension
• universal solvent

4. Which explanation best explains how the properties of water are affecting this living thing?

• The water molecules are polar. This creates cohesion and makes the molecules stick to the feet of the spider. This allows the spider to walk on the surface of water.
• The hydrogen bonds between the water molecules create a property called surface tension. This makes the surface of water somewhat resistant to external forces and allows the spider to run across the water.

5. An organic compound contains

• carbon.
• oxygen.
• salt.
• water.

6. Water is often called the "universal solvent". One reason this is important to living things because -

• it means water cools down very quickly.
• water can't dissolve many other substances.
• water is the solvent for blood, sweat, tears, and saliva
• it allows Mr. Varner to make his sweet tea as sweet as possible. (DON'T PICK THIS ONE!!)

7. Choose all the apply. Which of the following are the FOUR major biomolecules?

• carbohydrates
• lipids
• nucleic acids
• proteins
• acids

8. A professional body builder would most likely want to increase thier consumption (intake) of what macromolecule?

• Lipids - They would want to consume lots of fats so they always look oiled up.
• Nucleic acid - They would want to be able to pass thier massive gains onto thier babies.
• Proteins - They would want to eat more protein because protein helps build muscle and repair tissues.

9. Mr. Varner decides to become a dance aerobics instructor. A few hours before his first class, he remembers he should consume one of the macromolecules, but he can't remember which. Can you help him?

• Carbohydrates - He will need a source of quick energy.
• Proteins - He needs to have energy stored up in his body.
• Nucleic acid - He wants to be sure his genes look good for his first class.
• Lipids - Fats will provide him with a quick energy source.

10. Mrs. Kazio has officially become a "crazy chicken lady". She buys 50 more chickens and starts selling the eggs. She wants to be extra nerdy as she advertises to her new costumers. Which of the following would be a good slogan?

• Eggs are a great source of Lipids! They give will you a quick burst of energy in the morning!
• Eggs are an Egg-selent way to get the Nucleic Acids you need! They are rich in sugars & starches!
• Eggs are rich in Protein! Get beautiful hair and strong muscles!