DNA and Enzymes

• What is the function of the active site in proteins?

  It allows substrates to attach and facilitates reactions.
• How does the 'lock and key' method relate to enzyme activity?

  It describes how substrates fit into the active site of enzymes.
• What role do enzymes play in digestion?

  They act as catalysts to break down food.
• What is the genetic material found inside every cell?

  DNA
• What is DNA made of?

  DNA is a polymer made of two strands of nucleic acid.
• What is the structure of DNA?

  It is in the form of a double helix.
• What factors can affect enzyme action?

  Temperature, pH, substrate concentration, and enzyme concentration.
• What happens to enzyme activity as substrate concentration increases?

  The rate of enzyme activity increases until all enzymes are used.
• What is the effect of temperature on enzyme reactions?

  Temperature can influence the rate of enzyme activity.
• What are the steps in the experiment to test the effect of temperature on enzyme reaction?

  1. Place starch and amylase in a water bath at 37°C.
  2. After 5 minutes, mix them and insert a thermometer.
  3. Test for starch every 30 seconds using iodine solution.
  4. Record the time for complete digestion and observations.
  5. Repeat for precise readings and try with different enzymes.
• How do you test for sugars like glucose?

  Add Benedict's reagent and heat for 2 minutes.
• What indicates the presence of sugar when using Benedict's reagent?

  If sugar is present, it turns red.
• How do you test for starch?

  Add iodine solution to the sample.
• What color change indicates the presence of starch?

  It turns bluey-black.
• How do you test for protein?

  Add Biuret reagent to the sample.
• What color indicates the presence of protein when using Biuret reagent?

  It turns purple.