Biochemical Reactions in Digestion
Introduction:
Digestion is the mechanical and chemical breakdown of food into smaller molecules that can be absorbed and used by the body.
Key Points:
- Three main types of biochemical reactions occur during digestion: hydrolysis, oxidation-reduction, and decarboxylation.
- Hydrolysis involves the breakdown of large molecules into smaller ones by the addition of water. This reaction is catalyzed by enzymes such as amylases, proteases, and lipases.
- Oxidation-reduction reactions involve the transfer of electrons between molecules. These reactions occur during the breakdown of carbohydrates and fats.
- Decarboxylation reactions involve the removal of carbon dioxide from a molecule. These reactions occur during the breakdown of amino acids.
Main Concepts:
The breakdown of food provides the body with energy and nutrients. The biochemical reactions that occur during digestion allow these molecules to be absorbed and used by the body.
The three types of biochemical reactions that occur during digestion are essential for proper nutrition. Deficiencies in these reactions can lead to malnutrition and other health problems.
Experiment: Biochemical Reactions in Digestion
Materials:
Potatoes Potato starch solution
Iodine solution Salivary amylase
Test tubes Graduated cylinder
Procedure:
1. Cut potatoes into small cubes and boil them until soft.
2. Mash the boiled potatoes and make a potato starch solution by mixing 10 grams of potato mash with 100 mL of water.
3. Label three test tubes as "Sample A," "Sample B," and "Sample C."
4. Add 10 mL of potato starch solution to each test tube.
5. Add 5 drops of iodine solution to Sample A. Observe the color change.
6. Add 5 drops of salivary amylase to Sample B. Mix well and let it stand for 10 minutes. Then, add 5 drops of iodine solution. Observe the color change.
7. Keep Sample C as a control. Do not add any amylase or iodine to it.
Observations:
Sample A: Initially, the solution will turn blue-black, indicating the presence of starch. Sample B: After adding amylase, the solution will turn yellow or light brown, indicating the absence of starch.
* Sample C: The solution will remain blue-black, confirming the presence of starch.
Explanation:
The change in color from blue-black to yellow or light brown in Sample B indicates that the salivary amylase has broken down the starch molecules into smaller molecules, such as glucose, which cannot be detected by the iodine solution. This demonstrates the biochemical reaction of digestion, where enzymes (such as amylase) break down complex carbohydrates (such as starch) into simpler sugars that can be absorbed and used by the body.
Significance:
This experiment provides a simple and visual demonstration of the biochemical reactions involved in digestion. Understanding these reactions is essential for food science, nutrition, and human health, as it helps us comprehend how the body processes different types of food and extracts the nutrients it needs.