Chapter 2.4-2.5 Quiz Biology I Coach Cardona ID:A

1. Chemical reactions change substances into different substances by

A. conserving matter between the substances
B. strengthening electrical charges of substances
C. breaking and forming chemical bonds
D. changing a solvent into a solute

2. Identify the reactants in the following chemical reaction: 6H₂O + 6CO₂  ---> C₆H₁₂O₆ + 6O₂

a. 6H₂O and 6CO₂
b. 6CO₂ and C₆H₁₂O₆
c. 6H₂O, C₆H₁₂O₆, and 6O₂
d. C₆H₁₂O₂ and 6O₆

3. What is the term for the amount of energy that needs to be added for a chemical reaction to start?

A. reactant energy
B. activation energy
C. bond energy
D. chemical energy

4. Which phrase best describes an exothermic reaction?

A. forms products with higher bond energy than reactants
B. releases more energy than it absorbs
C. is in a state of equilibrium
D. does not absorb any energy

5. Which phrase best describes the effect of a catalyst on a chemical reaction?

A. increases the temperature
B. decreases the reaction rate
C. decreases the activation energy
D. increases the volume of reactants

Which statement best describes the graph shown?

A. Less energy is needed to start reaction B.
B. The original reaction is catalyzed.
C. More energy is released by the original reaction.
D. Reaction B occurs at a slower rate.

7. Enzymes affect chemical reactions in living organisms by

A. changing the direction of a reaction.
B. increasing the temperature range.
C. weakening bonds in reactants.
D. breaking down all molecules into starch.

8. Changes in temperature and pH can decrease an enzyme's activity by breaking

A. sulfur-sulfur bonds
B. amino acids
C. hydrogen bonds
D. peptide bonds

9. The specific reactants that an enzyme acts on are called

A. substrates
B. catalysts
C. proteins
D. amino acids

10. One of the most important processes for life on Earth, photosynthesis, is

A. Proteins
B. Lipids
C. Exothermic
D. Endothermic