Question

List the three dietary macronutrients, the foods in which each predominates, what subunits compose them, and some of their functions in cells.

Answer 1

Three macro nutrients are Carbohydrate, protein and lipids.

Carbohydrates;

These are the primary energy source of the body. The structure is made of carbon and hydrogen. Classified as

• monasaccharides like glucose, fructose, galactose etc,
• disaccharide like sucrose, lactose, maltose etc.
• oligosaccharide
• polyscahharide like starch, cellulose etc.

These are the major contributor of ATP via glycolysis, TCA cycle and mitochondrial electron transport chain & oxidative phosphorylation. It is can be a part of membrane protein, antibodies and coagulation factor.

Carbohydrate rich food- Tuber or root vegetable like Potato, Carrot

Protein;

These are the building blocks of the body. Monomeric units are amino acid grouped as essential and non-essential. Essential are the one which are not produced by the body and need to be aqcuired from outside sources and non-essential are the one which are produced by the body. The basic structure of amino acid contain a basic (NH2) and one acidic group (COOH). The number of basic/ acid ratio varies as per the type of amino acid. It is classified as Neutral (Aliphatic, Aromatic, Heterocyclic and Sulphur containing), Bassic and Acidic.

It acts as facilitator in different reaction in the form of enzyme and hormone. It acts as a transporter and cell receptors. Help in defense mechanism as immunoglobulin. Form actin and myosin for muscle contraction.

Protein rich food- Egg, Meat, Fish

Lipids:

These are made of alcohol and fatty acid unit and in some cases phosphoric acid, nitrogenous base and carbohydrate.

• Source of energy
• Fat soluble vitamin carrier like Vit A, D, E, K
• It supports cell Fluid Mosaic Model.
• Lipoproteins acts as triglyceride and cholesterol carrier

Lipid rich food- Oils and fat (like butter, ghee), Fish oil (unsaturated fatty acid)