Exploring Biomolecules in Bio141 Lab

Dr. Bodhi demonstrates how to use different reagents to test biomolecules. The video covers setting up test tubes with positive and negative controls, adding water and reagents, and conducting tests with Lugol's, Biuret, Sudan IV, and Benedict's solutions. Each reagent is used to identify specific biomolecules: starch, proteins, lipids, and glucose, respectively. The video explains the reactions and color changes that indicate the presence of these biomolecules.

What is the primary purpose of setting up positive and negative controls in the biomolecules demonstration?

• To make the experiment look more colorful

• To use up all the reagents

• To compare the test results with known outcomes

• To ensure the test tubes are clean

Tags

NGSS.HS-ETS1-3

What is added to the test tubes initially in the demonstration?

• Proteins

• Starch

• Water

• Reagents

Which reagent is used to test for the presence of starches?

• Biuret

• Sudan IV

• Lugol's solution

• Benedict's solution

What color change indicates a positive reaction with Lugol's solution?

• Blue to orange

• Blue to purple

• Amber to black

• Red to green

Which reagent is used to test for proteins?

• Lugol's solution

• Biuret

• Benedict's solution

• Sudan IV

Why is it recommended to wear gloves when handling Sudan IV solution?

• It is very slippery

• It is very hot

• It can stain the skin

• It is very cold

What is the indicator for lipids in the demonstration?

• Lugol's solution

• Biuret

• Sudan IV

• Benedict's solution

What is added to the Benedict's solution to observe a reaction?

• Protein

• Starch

• Glucose

• Lipid

What color change indicates a positive reaction with Benedict's solution?

• Amber to black

• Blue to orange

• Blue to purple

• Red to green

What is the initial color change observed with a small amount of glucose in Benedict's solution?

• Red to orange

• Blue to green

• Amber to black

• Blue to purple