Difficulty: Medium
Correct Answer: All of the above
Explanation:
Introduction / Context:
Carbohydrates, lipids and proteins are three major classes of substances that play central roles in living organisms. They are involved in energy storage, structural support, transport, signalling and many other functions. Different textbooks describe them using overlapping terms such as macromolecules, biomolecules and macronutrients. This question asks you to recognise that more than one of these labels can apply at the same time.
Given Data / Assumptions:
Concept / Approach:
Carbohydrates, lipids and proteins are large, complex molecules built from smaller subunits. Because of their size, they are often called macromolecules. They are produced by living organisms and are therefore biomolecules. In the context of human nutrition, they are required in relatively large amounts in the diet and so are called macronutrients, in contrast to micronutrients such as vitamins and minerals, which are needed in smaller amounts. Since each of these terms correctly describes a different aspect of the same compounds, the best answer is that all of the labels apply.
Step-by-Step Solution:
Step 1: Consider macromolecules. This term refers to very large molecules with high molecular weight, usually built from repeating smaller units. Carbohydrates like starch, proteins and many lipids fit this description.
Step 2: Consider biomolecules. This term covers any molecule that is produced by living organisms or is essential for life. Carbohydrates, lipids and proteins are central organic molecules in living cells and therefore qualify as biomolecules.
Step 3: Consider macronutrients. In nutrition, macronutrients are nutrients needed in gram quantities per day for energy and body building. Carbohydrates, fats and proteins are the classic macronutrients.
Step 4: Recognise that all three labels correctly apply to the substances mentioned in the question.
Step 5: Choose the option that states that all the previous categories are correct, namely all of the above.
Verification / Alternative check:
If you open a biology textbook, you will find a chapter on biological macromolecules describing carbohydrates, lipids and proteins as macromolecules and biomolecules. In a nutrition or health science book, you will see the same three classes listed as macronutrients that supply energy and building blocks. Because both disciplines talk about the same substances but from different viewpoints, they use slightly different terms. This consistency across subjects confirms that all three descriptions are valid.
Why Other Options Are Wrong:
Choosing only macromolecules would ignore the nutritional term macronutrients and the broader biological term biomolecules.
Choosing only biomolecules would miss the fact that their large size and dietary importance are also emphasised in science education.
Choosing only macronutrients would focus only on nutrition and ignore their classification in molecular biology.
Trace elements refers to minerals such as iron and iodine that are required in minute quantities, not to carbohydrates, lipids or proteins.
Common Pitfalls:
A common mistake is to think that a question like this must have only one technically correct label and that all of the above is a trick. In biology, however, many concepts can be described accurately with more than one term depending on the context. When you see that each individual option is correct on its own and there is no conflict between them, it is usually safe to choose the combined option. Training yourself to check each statement carefully will help you handle such questions with confidence.
Final Answer:
Carbohydrates, lipids and proteins are at the same time Macromolecules, Biomolecules and Macronutrients, so all of the above apply.
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