Week 4 1. Which kind of molecule provides building blocks for tissues, transports other molecules, and helps regulate certain reactions in the human body? Lipid Fat Carbohydrate Protein

2. Which molecules have a primary function of providing a rapidly available energy source for living things? Proteins Carbohydrates Fats Amino acids

3. Which compounds join together to form proteins? Nucleic acids Amino acids Simple sugars Fatty acids

4. Which of the following environmental changes is MOST likely to slow chemical reactions in cells? Increased temperature Decreased temperature An increase in the number of substrate molecules in solution Neutralization of an acidic environment

5. Glucose is formed by plants when they carry out photosynthesis 5. Glucose is formed by plants when they carry out photosynthesis. Glucose is an example of a Protein Carbohydrate Lipid Nucleic acids

6. ADP must combine with which of the following in order to regenerate ATP? A free phosphate A positive ion An adenine base A molecule of glucose

7. Water is known as the universal solvent 7. Water is known as the universal solvent. What property of water makes it such an excellent solvent? Water is normally a liquid at room temperature. Water molecules are polar. Water molecules are nonpolar. Water is less dense as a solid than as a liquid.

8. A group of macromolecules includes waxy or oily compounds that do not dissolve in water. In organisms, some of these compounds store energy while others serve an important function in cell membranes. Which group of macromolecules has these properties? Carbohydrates Nucleic acids Proteins Lipids

9. You Prepare a mixture of salt, sugar, and water 9. You Prepare a mixture of salt, sugar, and water. After stirring the contents, you observe that the salt and sugar have dissolved in the water. Which of the following accurately summarizes your observations about this mixture? Water is a solute. Salt is a solute, but not sugar. Sugar is a solute, but salt is not. Both sugar and salt are solutes.

10. Which of the following factors affect enzyme activity? Temperature and pH only Amount of enzyme and substrate only Temperature and amount of enzyme only Temperature, pH, and amount of both enzyme and substrate