20 Questions About The Digestive System With Answers Related

Review 20 Questions About The Digestive System With Answers related questions and content

Four test tubes, each containing 2cm3 of amylase solution are treated as follows: 1 boiled, then cooled to 1 °C 2 boiled, then cooled to 25 °C 3 frozen, then warmed to 1 °C 4 frozen, then warmed to 25 °C 10 cm3 of starch solution were then added to each tube and after 5 minutes, 2 drops of iodine solution were added to each tube. Which row shows the results?

  • A. 1: blue-black, 2: blue-black, 3: yellow-brown, 4: yellow-brown
  • B. 1: blue-black, 2: yellow-brown, 3: blue-black, 4: yellow-brown
  • C. 1: yellow-brown, 2: blue-black, 3: blue-black, 4: yellow-brown
  • D. 1: yellow-brown, 2: yellow-brown, 3: blue-black, 4: blue-black
Correct Answer: A

Rationale: Boiling denatures the enzyme permanently, while freezing does not affect its activity once thawed.