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Mindful Eating: A Pathway to Health - Nutrients in Food: Carbohydrates, Proteins, and Fats

Grade 6CBSE

Review the key concepts, formulae, and examples before starting your quiz.

🔑Concepts

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Carbohydrates are the primary energy-giving nutrients. They are found in food as starch and sugars. The chemical formula for glucose, a simple carbohydrate, is C6H12O6C_6H_{12}O_6.

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Proteins are known as body-building foods. They are essential for the growth and repair of body tissues. In the lab, we test for proteins using Copper Sulphate (CuSO4CuSO_4) and Caustic Soda (NaOHNaOH).

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Fats also provide energy to the body. In fact, fats provide much more energy as compared to the same amount of carbohydrates. The presence of fats is indicated by an oily patch on paper.

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The Iodine test is used to detect starch. When iodine (I2I_2) solution is added to a food item containing starch, it turns blue-black.

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Balanced Diet: Mindful eating involves consuming a diet that contains all the nutrients in the correct proportion, including roughage and water (H2OH_2O).

📐Formulae

Starch+I2→Blue-Black Color\text{Starch} + I_2 \rightarrow \text{Blue-Black Color}

Protein+CuSO4+NaOH→Violet Color\text{Protein} + CuSO_4 + NaOH \rightarrow \text{Violet Color}

Energy Value of Fats>Energy Value of Carbohydrates\text{Energy Value of Fats} > \text{Energy Value of Carbohydrates}

Total Energy (kcal)≈(4×g of Carbs)+(4×g of Protein)+(9×g of Fat)\text{Total Energy (kcal)} \approx (4 \times \text{g of Carbs}) + (4 \times \text{g of Protein}) + (9 \times \text{g of Fat})

💡Examples

Problem 1:

A student adds 2 drops of CuSO4CuSO_4 and 10 drops of NaOHNaOH to a food extract. The solution turns violet. Which nutrient is present in the food?

Solution:

Proteins are present.

Explanation:

The change of color to violet indicates a positive Biuret test, which confirms the presence of peptide bonds in proteins using Copper Sulphate (CuSO4CuSO_4) and Sodium Hydroxide (NaOHNaOH).

Problem 2:

If 10 g10 \text{ g} of a food item contains only carbohydrates, calculate the approximate energy provided given that 1 g1 \text{ g} of carbohydrate releases 4 kcal4 \text{ kcal} of energy.

Solution:

10 g×4 kcal/g=40 kcal10 \text{ g} \times 4 \text{ kcal/g} = 40 \text{ kcal}

Explanation:

Carbohydrates are energy-giving foods where each gram typically yields about 4 kcal4 \text{ kcal} of energy.

Problem 3:

Why does a piece of white bread turn blue-black when a drop of Iodine solution is placed on it?

Solution:

Due to the presence of Starch.

Explanation:

Bread contains starch, a complex carbohydrate. The chemical reaction between starch and Iodine (I2I_2) produces a characteristic blue-black complex.