The correct option is (a) 1 only.
Explanation
Digestion is the biochemical process of breaking down complex food substances into simpler, absorbable forms. Various factors, including food preparation methods and dietary components like water and roughage, significantly influence the efficiency of this process.
Statement-wise Analysis
- Statement 1 is Correct: Cooking generally makes food easier to digest. Heat breaks down complex molecules such as starch (gelatinization) and proteins (denaturation), making them more accessible to digestive enzymes. It also softens tough connective tissues in meat and cellulose in plants, facilitating mechanical breakdown during chewing.
- Statement 2 is Incorrect: Roughage, also known as dietary fiber, consists mainly of cellulose from plant cell walls. Humans lack the enzyme cellulase required to digest it. Therefore, roughage does not provide enzymes or nutrients. Its primary function is to add bulk to the diet, retain water, and stimulate peristalsis (muscle contractions) to prevent constipation.
- Statement 3 is Incorrect: Water is essential for digestion and absorption. Digestion is a hydrolytic process, meaning it requires water to break chemical bonds. Furthermore, water acts as a solvent that dissolves nutrients, allowing them to be absorbed by the intestinal lining and transported through the blood. It facilitates, rather than hinders, nutrient absorption.
Key Takeaway
Cooking aids digestion by breaking down complex structures; roughage aids bowel movement mechanically but provides no enzymes; and water is the essential medium for hydrolysis and nutrient absorption.