PREVIOUSLY ASKED IN:
WBPSC Miscellaneous Preliminary 2019
Answer
Amylase
Explanation
In humans, the digestion of food begins in the mouth. As soon as food is chewed, it mixes with saliva produced by the salivary glands. Saliva contains the enzyme salivary amylase (also known as ptyalin). This is the very first enzyme to encounter the food, and its primary function is to begin the chemical breakdown of complex carbohydrates (starches) into simpler sugars like maltose.
Key Points
- > Saliva also contains Lysozyme, an antibacterial enzyme that helps destroy pathogens in the food.
- > Pepsin is an enzyme produced in the stomach that initiates the digestion of proteins.
- > Trypsin is secreted by the pancreas and continues the digestion of proteins in the small intestine.
- > The human body lacks Cellulase, meaning we cannot digest cellulose (plant fibers) found in raw grass or leaves.
- > No protein or fat digestion occurs in the mouth; only carbohydrate digestion begins there.
Additional Information
Major Digestive Enzymes in Humans
| Enzyme | Secreted By | Digests | Site of Action |
|---|---|---|---|
| Amylase (Ptyalin) | Salivary glands | Carbohydrates (Starch) | Mouth |
| Pepsin | Stomach glands | Proteins | Stomach |
| Lipase | Pancreas | Fats (Lipids) | Small Intestine |
| Trypsin | Pancreas | Proteins | Small Intestine |
Memory Tips
- Mouth First: Food enters the mouth first, mixing with saliva. Saliva = Salivary Amylase.
- Pepsin for Protein.
- Lipase for Lipids (Fats).