Unit 3 review

Which phrase best describes an exothermic chemical reaction?

• Does not absorb any energy.

• Forms products with higher bond energy than reactants.

• Is in a state of equilibrium.

• Releases more energy than it absorbs.

Identify the products in this reaction: 6H₂O + 6CO₂ → C₆H₁₂O₆ + 6O₂

• 6H₂O and 6CO₂

• 6CO₂ and C₆H₁₂O₆

• C₆H₂O, C₆H₁₂O₆, and 6O₂

• C₆H₁₂O₆ and 6O₂

In the enzyme-substrate complex pictured below, what is happening during the second picture?

• The catalyzed reaction is releasing a product.

• The enzyme is breaking bonds in the substrate.

• The enzyme is keeping the bonds the same in the substrate.

• The substrate is beginning to bind to the enzyme.

If the activation energy of a biochemical reaction is lowered, then

• the reaction will happen faster.

• the reaction will happen more slowly.

• more energy will need to be absorbed.

• the rate of the reaction will be unaffected.

In the graph to the right, an increase in temperature results in

• a decrease in the required activation energy.

• an increase in reaction rate.

• a decrease in the rate of reaction.

• an increase in both the reaction rate and activation energy.

Which macromolecule found in the food you eat will your cells break down first to get ATP?

• Carbohydrates

• Lipids

• Proteins

• Nucleic Acids

Which phrase best describes the function of the ATP molecule?

• absorbs energy

• increases energy

• stores energy

• creates energy

Energy is released from an ATP molecule for cellular processes when it

• converts a phosphate group to ADP.

• attaches an extra phosphate group.

• loses a phosphate group.

• produces a sugar molecule.

Which of the following reactions directly provides chemical energy for most cell functions?

• ADP → ATP + P

• ADP + P → ATP

• ATP + P → ADP

• ATP → ADP + P

Where does your body get the energy for reattaching a third phosphate to ADP, creating ATP?

• from the sun

• usually from carbs

• from nucleic acids

• from breaking ATP