Enzyme Function and Activity Quiz

Where does protein digestion begin in the human alimentary canal?

• Large intestine

• Mouth

• Small intestine

• Stomach

What role do enzymes play in chemical reactions?

• They increase the activation energy

• They change the shape of substrates

• They act as inhibitors

• They act as biological catalysts

What is the lock and key mechanism in enzyme activity?

• Enzymes can bind to any substrate

• Enzymes are permanently altered after reactions

• Enzymes and substrates have complementary shapes

• Enzymes change shape to fit substrates

Why is lactose not absorbed in the small intestine of lactose-intolerant individuals?

• Lactose is already broken down in the stomach

• Lactose is absorbed in the large intestine

• The enzyme to break down lactose is absent

• Lactose is too small to be absorbed

What is the result of lactose not being broken down in lactose-intolerant individuals?

• No effect

• Improved digestion

• Diarrhea and gas

• Increased energy levels

What happens to enzymes at temperatures above 60 degrees Celsius?

• They are denatured

• They increase reaction rates

• They become more active

• They change substrates

How does an increase in temperature affect enzyme activity?

• It increases enzyme activity

• It reduces substrate collisions

• It decreases kinetic energy

• It denatures all enzymes

Which factor, other than temperature, affects enzyme activity?

• Enzyme size

• Substrate color

• pH level

• Light intensity

At what temperature does lactase work most effectively in humans?

• 25 degrees Celsius

• 37 degrees Celsius

• 50 degrees Celsius

• 60 degrees Celsius

What is the optimal pH for most enzyme-controlled reactions?

• pH 7

• pH 5

• pH 9

• pH 3