Biological Molecules Testing Quiz
13 Questions
0 Views

Choose a study mode

Play Quiz
Study Flashcards
Spaced Repetition
Chat to Lesson

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What color change would indicate a positive result for a Benedict's test?

  • Orange (correct)
  • Brick Red (correct)
  • Green/Yellow
  • Blue

    • What color change would indicate a positive result for a Biuret's test?

  • Orange
  • Green/Yellow
  • Purple (correct)
  • Blue

    • What color change would indicate a positive result for the Iodine test?

  • Clear
  • Orange/Brown
  • Blue/Black (correct)
  • Blue

    • What color change would indicate a positive result for the Emulsion test?

    <p>Cloudy White (B)</p> Signup and view all the answers

    Which test is used to detect the presence of simple sugars like glucose?

    <p>Benedict's test (B)</p> Signup and view all the answers

    Which of the following is a positive result for the Benedict's test for glucose?

    <p>Brick red (C)</p> Signup and view all the answers

    What is the purpose of grinding a food sample in a pestle and mortar before testing it?

    <p>To increase the surface area of the food, allowing for faster and more efficient chemical reactions to occur. (A)</p> Signup and view all the answers

    What is the purpose of shaking the test tube with ethanol in the emulsion test for lipids?

    <p>To dissolve the sample and allow for the emulsion to form. (A)</p> Signup and view all the answers

    What is the correct order of steps for performing the Iodine test for starch?

    <p>Prepare food sample, place sample on spotting tile, add iodine solution, observe color change. (C)</p> Signup and view all the answers

    What is the correct order of steps for performing the Biuret test for protein?

    <p>Prepare food sample, add Biuret solution, mix, observe colour change. (B)</p> Signup and view all the answers

    Which of the following tests is used to detect the presence of simple sugars, such as glucose?

    <p>Benedict's test (D)</p> Signup and view all the answers

    Which biological molecule is detected by the Biuret test?

    <p>Protein (C)</p> Signup and view all the answers

    What is the main purpose of the water bath in the Benedict's test?

    <p>To provide a consistent temperature for the reaction to occur. (C)</p> Signup and view all the answers

    Flashcards

    Benedict’s Test

    A test to detect glucose in food samples using Benedict’s solution.

    Iodine Test

    A test for starch in food samples that uses iodine solution and changes color.

    Biuret’s Test

    A test used to identify proteins in food samples by observing color change with Biuret's solution.

    Emulsion Test

    Test for lipids, using ethanol and observing a cloudy emulsion after adding water.

    Signup and view all the flashcards

    Positive Benedict’s Result

    Indicates the presence of glucose via color changes: green, yellow, orange, or brick red.

    Signup and view all the flashcards

    Negative Benedict’s Result

    No glucose present; solution remains blue after testing.

    Signup and view all the flashcards

    Positive Biuret’s Result

    Indicates proteins with a color change from blue to purple when Biuret's solution is added.

    Signup and view all the flashcards

    Positive Iodine Result

    Indicates starch presence by turning blue/black when iodine solution is added.

    Signup and view all the flashcards

    Benedict's Test

    Test used to detect simple sugars like glucose.

    Signup and view all the flashcards

    Positive Result in Benedict's Test

    Solution turns color: green/yellow, orange, or brick red.

    Signup and view all the flashcards

    Iodine Solution Test

    Used to test for starch in food samples.

    Signup and view all the flashcards

    Biuret's Test

    Test for proteins; solutions change color if proteins present.

    Signup and view all the flashcards

    Study Notes

    Starter Activity - 5 Minutes

    • List the tests for identifying biological molecules
      • Glucose
      • Starch
      • Protein
      • Lipids
    • Bonus task: State the positive and negative results for each test.

    Lesson - Testing an Unknown Sample

    • Lesson Outcomes:
      • Bronze: Recall different food tests.
      • Silver: Complete four different food tests.
      • Gold: Identify different biological molecules in the food.

    Food Testing Procedure

    • Prepare the food sample: Grind the food sample (e.g., bread) with water in a mortar and pestle.
    • Filter the sample: Use filter paper to filter the ground food sample into a beaker.
    • Add water and mix: In food testing procedures, add 5ml of water and mix the sample to prepare for further tests.

    Food Testing Methods

    • Glucose: Use test tubes and water baths.
    • Starch: Use a spotting tile with iodine solution.
    • Protein: Use a spotting tile with Biuret's solution.
    • Lipids: Use test tubes for the emulsion test.

    Glucose Test - Benedict's Test

    • Purpose: To test for simple sugars (e.g., glucose).
    • Procedure:
      1. Prepare a food sample.
      2. Add 5 mL of the food sample to a test tube.
      3. Add 5 mL of Benedict's solution and mix.
      4. Heat the test tube in a water bath at 80°C for 10 minutes.
      5. Record the colour change.
    • Results:
      • Negative (no glucose): Blue
      • Low glucose concentration: Green/yellow
      • Medium glucose concentration: Orange
      • High glucose concentration: Brick red

    Starch Test - Iodine Test

    • Purpose: To test for starch.
    • Procedure:
      1. Prepare a food sample.
      2. Place a small amount of the food sample on a spotting tile.
      3. Add 2-3 drops of iodine solution to the food sample.
      4. Observe the colour change.
    • Results:
      • Negative (no starch): Orange/brown
      • Positive (starch present): Blue/black

    Protein Test - Biuret Test

    • Purpose: To test for protein.
    • Procedure:
      1. Prepare a 5 mL sample of the food.
      2. Add 5 mL of Biuret's solution.
      3. Mix the solution thoroughly.
      4. Observe the colour change.
    • Results:
      • Negative (no protein): Blue
      • Positive (protein present): Purple

    Lipid Test - Emulsion Test

    • Purpose: To test for lipids (fats).
    • Procedure:
      1. Place a small amount of the food sample in a test tube.
      2. Add 5 mL of ethanol and shake to dissolve the lipid.
      3. Add 5 mL of water and mix the solution thoroughly.
      4. Observe the colour change.
    • Results:
      • Negative (no lipids): Clear solution
      • Positive (lipids present): Cloudy white solution

    Studying That Suits You

    Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

    Quiz Team

    Related Documents

    Food Testing Methods - PDF

    Description

    Test your knowledge on the different methods used to identify biological molecules such as glucose, starch, protein, and lipids. This quiz will help reinforce the food testing procedures and the expected positive and negative results for each test. Perfect for students looking to review key concepts in biology.

    More Like This

    Use Quizgecko on...
    Browser
    Open
    Browser
    Browser