Unit 3 Energy Flow Test

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

• 6H₂O, C₆H₁₂O₆, and 6O₂

• C₆H₁₂O₆ and 6O₂

Chemical reactions that absorb more energy than they release are considered to be.

• exothermic

• catalyzed

• endothermic.

• anabolic

The activation energy needed for a chemical reaction is decreased by the presence of a.

• catalyst

• reactant

• product

• substrate

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.

The molecule that an enzyme binds to is known as its.

• substrate

• monomer

• polymer

• complimentary base

Reactants bind to enzymes at the.

• substrate

• product

• activation energy

• active site

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.

Fill in the blank using the terms in the word bank on your answer sheet. Chemical reactions change A and make B . The activation C is required in order for a chemical reaction to occur. Chemical reactions can be classified as D or E . An example of a reaction that releases more energy than it absorbs is F . An example of a reaction that absorbs more energy than it releases is G . All chemical reactions must break or form H .