AS Biology Enzymes

Enzymes catalyze reactions by ___________ activation Energy.

• Increasing

• Decreasing

• Stopping

• Destroying

Why does enzyme activity decline at high temperatures?

• denaturation

• decreased kinetic motion

• increase H-bonding

• active sites become full

At low temperatures enzyme activity declines because of:

• Denaturation

• Decreased Kinetic Motion

• Increased H-Bonding

• Dissociation of Ionic Compounds

When a molecule can occupy the same active site as the substrate, a situation called __________________ can result.

• competitive inhibition

• end-product inhibition

• non-competitive inhibition

• feedback inhibition

Which explanation best fits the graph for pH's effect on an enzyme?

• As the pH gets closer to neutral more H-Bonds are broken

• Larger numbers of H+ & OH- ions distort the active site

• There are more collisions between substrates and active sites near the optimal pH

• Low pHs cause more H-Bonds to happen near the active site

Enzymes are capable of increasing the rate of a chemical reaction within a living cell.  Enzymes accomplish this through which of the following means?

• reducing the number of products   
• reducing the activation energy
• increasing the temperature of the cell
• increasing the concentration of reactants 

What 3 letters do enzymes typically end in?

• -ose
• -ase
• -ese
• -tic

After the enzyme and substrate bind together and perform the reaction, what does the substrate become?

• a substrate
• an enzyme
• a product
• an active site

In the diagram, what is letter A?

• product

• substrate

• enzyme-substrate complex

• enzyme-product complex

Based on the graph, what is the optimal temperature for this enzyme?

• 15^oC

• 40^oC

• 30^oC

• 48^oC