Enzymes

The enzyme will no longer be able to catalyze the reaction with the substrate.

The active site's shape matches the substrate. If the shape changes, the substrate can't bind, so the enzyme can't catalyze the reaction.

The substrate will change its shape to match the enzyme.: Substrates don't change shape to fit an altered enzyme.

The products made from the enzyme and the substrate will be changed.: If the substrate can't bind, no products are made at all.

The enzyme will be able to bind to more diverse substrates than before.: Substrates need a specific fit, so a changed shape doesn't let the enzyme bind more substrates.

Model B

The substrate is split into products while the enzyme remains unchanged and can be reused, as shown in Model B.

Model A: The products and enzyme do not have the correct final structures.

Model C: The enzyme and substrate remain joined; an enzyme is not permanently consumed in the reaction.

Model D: The substrate is not converted into the expected products and the enzyme is altered.

have a complementary shape to the substrate

The active site must fit the substrate's shape so the substrate can bind and the enzyme can lower activation energy.

be occupied by an inhibitor: An inhibitor occupying the active site can prevent substrate binding.

increase the activation energy level: Enzymes lower, not increase, activation energy.

cause the enzyme to be destroyed in the reaction: Enzymes are not destroyed by the reactions they catalyze.

The enzyme is able to optimally function and bind to its substrate at around 45 °C.

Enzyme activity on the graph is highest at about 45 °C, so the enzyme functions optimally near that temperature.

The enzyme is denatured and can no longer bind to its substrate between 20 and 40 °C.: The enzyme is still active at these temperatures.

The enzyme can only bind to its substrate at temperatures between 30 and 60 °C.: The enzyme is still active at temperatures outside this range.

The enzyme can no longer bind to its substrate at temperatures greater than 60 °C.: The enzyme is still active at 70 °C.

Amylase will be unable to function in the stomach.

The change to the stomach's acidic pH will denature amylase, so it will no longer function.

Amylase will continue to break down sugars in the stomach.: The pH change causes amylase to stop functioning, so it no longer breaks down sugars.

Amylase will help the stomach break down proteins.: Amylase does not digest proteins, and the pH change alters it so it is no longer functional.

Amylase will be recycled for use in other systems.: The pH change alters amylase, and it will no longer function.

It becomes less effective because it is inhibited by the change in pH from the stomach to the intestines.

An enzyme has an optimal pH range. The shift in pH from the stomach to the intestine causes this lipase to become less effective.

It becomes less effective because it is used up by fats in the stomach.: Enzymes are reused if they are not denatured.

It becomes more effective because it acquires energy for more reactions from fats.: Enzymes lower the activation energy of reactions; they do not acquire energy.

It becomes more effective because it changes shape and is able to break down other materials in the intestines.: A change in an enzyme's shape indicates denaturation, which makes it less effective.

The substrates will bind together to form a product, and the enzyme will be unchanged.

In enzymatic reactions, the substrates are changed into a product, while the enzyme is unchanged and can be reused.

The substrates will bind together to form a product, and the enzyme will be denatured.: Enzymes are reused in chemical reactions; they are not denatured by catalyzing them.

The enzymes and substrates will all bind together to form one product.: Enzymes detach from the substrates once the reaction is complete.

The enzyme will become the product and both substrates will be released.: The substrates, not the enzyme, become the product.