Enzyme Part 1 Review

Purple shape

blue shape

orange and green shapes

All enzymes end in

• -ose

• -ase

• -tion

• -osis

Using the names of the reactants and products (instead of chemical formulae), write

a chemical equation for the reaction catalyzed in Model 1.

• Lactase => Lactose

• Lactose => Lactase

• Lactase => Glucose + Galactase

• Lactose => Glucose + Galactase

Referring to the chemical reaction you wrote for the question above, is lactase a

reactant, a product, or neither?

• Reactant

• Product

• Neither

Describe the role the enzyme lactase played in the reaction.

• Lactase catalyzed the reaction in which the complex sugar (disaccharide)

  lactose was broken into simple sugars glucose and galactose

  (monosaccharides).

• Lactase pulled apart lactose.

• Lactase created glucose and galactose.

• Lactase did not play a role.

What do you think could happen to the enzyme lactase at the end of the reaction?

• It disappears and is not used again.

• It is destroyed in the process.

• Lactase could be used again to cause another molecule of lactose to break

  into glucose and galactose.

• It turns into glucose and galactose.

Suppose the image below is a model of a different disaccharide, sucrose. Would lactase be able to break down sucrose? Explain your answer in terms of the model.

• Yes, the active is the same shape, so the substrate (sucrose) will fit with the enzyme (lactase).

• Yes, the active site is differently shaped, so the substrate (sucrose) will fit with the enzyme (lactase).

• No, the active site is the same shape, so the substrate (sucrose) will not fit with the enzyme (lactase).

• No, the active site is differently shaped, so the substrate (sucrose) will not fit with the the enzyme (lactase).

How does the presence of enzymes change the energy needed for a reaction to occur?

• It lowers the energy required, making the reaction more likely to happen.

• It lowers the energy required, making the reaction less likely to happen.

• It increases the energy required, making the reaction more likely to happen.

• It increases the energy required, making the reaction less likely to happen.