Year 12 Bio - Periods 56-59

What is 'affinity' in the context of enzymes?

• The temperature at which an enzyme works best.

• The strength of attraction between an enzyme and its substrate.

• The speed at which an enzyme becomes denatured.

• The amount of product an enzyme can produce.

If an enzyme has a stronger affinity for its substrate, what does this mean?

• It will work slower.

• It will need more substrate to function.

• It will have a greater attraction to the substrate.

• It will break down the substrate more slowly.

What is the Michaelis-Menten constant (Km​)?

• The maximum rate of reaction.

• The substrate concentration at which the enzyme works at half its maximum rate.

• The optimum temperature for an enzyme.

• The amount of enzyme present.

If an enzyme has a high affinity for its substrate, what will its Km​ value be like?

• Very high.

• Very low.

• Unchanged.

• Not related to affinity.

What does a lower Km​ value indicate about an enzyme's affinity for its substrate?

• Lower affinity.

• Higher affinity.

• No affinity.

• It's denatured.

According to the text, what happens to all enzyme molecules at Vmax​?

• They are denatured.

• They are bound to substrate molecules.

• They are inactive.

• They are producing very little product.

What is the enzyme carbonic anhydrase known for?

• Breaking down proteins.

• Converting carbon dioxide from respiring tissue.

• Digesting carbohydrates.

• Producing oxygen.

How quickly can an enzyme like carbonic anhydrase convert substrate molecules into product?

• Hundreds of times per second.

• Thousands of times per second.

• Millions of times per second.

• Tens of times per second.

Based on Table 3.1, which enzyme has the highest Vmax​ (arbitrary units)?

• Carbonic anhydrase

• Penicillinase

• Chymotrypsin

• Lysozyme

Based on Table 3.1, which enzyme has the lowest Km​ (µmol dm$^{-3}$)?

• Carbonic anhydrase

• Penicillinase

• Chymotrypsin

• Lysozyme