Question

Amylases in saliva begin the breakdown of carbohydrates into

• A. Fatty acid
• B. Polypeptides
• C. Amino acids
• D. Simple Sugars

Hint:

Remember the enzyme-substrate matches:
- Amylase $\rightarrow$ Carbohydrates $\rightarrow$ Simple Sugars.
- Protease/Pepsin $\rightarrow$ Proteins $\rightarrow$ Peptides/Amino Acids.
- Lipase $\rightarrow$ Lipids $\rightarrow$ Fatty Acids/Glycerol.

Answer 1

The Correct Option is D

Step 1: Understanding the Concept:
Digestion is the physiological process of breaking down complex, insoluble food macromolecules into smaller, soluble molecules that can be absorbed across the intestinal epithelium.
This process begins in the oral cavity through both mechanical chewing and enzymatic hydrolysis.

Step 2: Detailed Explanation:
Let us analyze the chemical digestion of nutrients:
1. Carbohydrate Digestion in the Mouth:
Saliva contains an enzyme called salivary amylase (historically known as ptyalin).
This enzyme specifically catalyzes the hydrolysis of $\alpha$-1,4-glucosidic bonds in complex polysaccharides like starch and glycogen.
This cleavage breaks down long-chain starch molecules into smaller, simpler saccharides, including the disaccharide maltose, trisaccharide maltotriose, and small dextrins.
These simpler, sweet-tasting compounds are classified as simple sugars (D).
Therefore, salivary amylase initiates the conversion of complex carbohydrates into simple sugars.
Let us review the other digestive end-products listed:
- Fatty acids (A): These are the end-products of lipid (fat) digestion, catalyzed by lipases in the stomach and small intestine, not amylases in the mouth.
- Polypeptides (B) and Amino acids (C): These are the intermediates and end-products of protein digestion, catalyzed by proteases (like pepsin, trypsin, and chymotrypsin) in the stomach and small intestine.

Step 3: Final Answer:
Salivary amylase begins the breakdown of complex carbohydrates into simple sugars in the mouth.
Therefore, the correct option is (D).