Appeared in: 2025 (3 sets)
Reduce carbohydrates, increase protein to check diabetes, older people may need greater carbohydrates reduction. An average Indian derives $61 - 64%$ of energy from consumption of food rich in carbohydrates. A study published in the Journal of Diabetes Care has recommended reducing this to $49 - 56%$ for remission or prevention of Type 2 diabetes, one of the leading cause of death worldwide. Along with reducing carbohydrate intake, the study suggests that one should also increase protein intake up to $14 - 20%$ of the total energy consumption. Fat should contribute not more than $21 - 27%$ of the total energy consumption. In simple words, $50%$ of the plate should consist of fruits and green vegetables, $25%$ carbohydrates, $25%$ food rich in protein. Type 1 diabetes is due to deficiency of insulin.
Answer the following questions :
(a) Write any two functions of carbohydrates.
(b) What are monosaccharides ?
(c) (i) Write the name of the deficiency diseases caused due to the lack of Vitamin D.
OR
(c) (ii) Name the hormone which maintains the glucose level within narrow limit in the blood.
✓ Verified CBSE Marking Scheme
Official Evaluation Steps & EL10 Insight
CBSE Class 12 Chemistry: Marking Scheme Solution
(a) Functions of Carbohydrates [1 Mark]
- Step 1 (Definition/Function): [0.5 Mark] Carbohydrates act as the primary source of energy for the body through the oxidation of glucose (e.g., $C_6H_{12}O_6 + 6O_2 \rightarrow 6CO_2 + 6H_2O + \text{Energy}$).
- Step 2 (Structural/Storage): [0.5 Mark] They provide structural support (e.g., cellulose in plant cell walls) and serve as energy storage molecules (e.g., starch in plants and glycogen in animals).
(b) Definition of Monosaccharides [1 Mark]
- Step 1 (Conceptual Definition): [1 Mark] Monosaccharides are the simplest carbohydrates that cannot be further hydrolyzed into smaller polyhydroxy aldehyde or ketone units. They possess the general formula $(CH_2O)_n$, where $n = 3-7$.
(c) (ii) Hormone Regulation [2 Marks]
- Step 1 (Identification): [1 Mark] The hormone responsible for maintaining blood glucose levels within a narrow limit is Insulin.
- Step 2 (Mechanism of Action): [1 Mark] Insulin is secreted by the $\beta$-cells of the Islets of Langerhans in the pancreas. It facilitates the uptake of glucose into cells and promotes glycogenesis (conversion of glucose to glycogen), thereby lowering blood glucose levels when they are high.
💡 EL10 Concept Insight:
Think of Insulin like a "key" that unlocks your body's cells so they can take in sugar (glucose) from your blood to use for energy, keeping your blood sugar levels steady like a thermostat keeps a room at the perfect temperature.