Energy Flow

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 called

• exothermic

• catalyzed

• endothermic

• activated

The activation energy needed for a chemical reaction is decreased by a

• catalyst

• reactant

• product

• substrate

In the lock-and-key model of enzyme function pictured, what is happening during the second step?

• 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

• this will not affect the rate of the reaction

• both A and B

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, 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

Chemical reactions change _____ and produce products .

• Reactants

• Physical properties

• Bonds

• Energy