What are the basic structural units of proteins?

JODHPUR AIIMS SNO-2018

Biochemistry & Nutrition

Easy

Appeared in: JODHPUR AIIMS SNO-2018

Explanation

Proteins are polymers, which are large molecules made up of repeating smaller units called monomers.
The specific monomers that link together to form proteins are amino acids.
There are 20 common amino acids found in the human body that combine in various sequences to create the vast diversity of proteins.
These amino acids are joined by covalent bonds known as peptide bonds to form long chains called polypeptides, which then fold into functional proteins.

Option A: Fatty acids are the basic building blocks of lipids (fats), not proteins. They are long hydrocarbon chains with a carboxyl group at one end.
Option B: Sucrose is a carbohydrate, specifically a disaccharide composed of glucose and fructose. It serves as a source of energy but is not a structural unit of proteins.
Option D: Peptides are short chains of amino acids linked by peptide bonds. While proteins are made of polypeptide chains, the peptide itself is a polymer, not the fundamental monomer. The most basic unit is the individual amino acid.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain The basic structural units of proteins as background academic context rather than a clinical decision trigger.
Understanding that proteins are made of amino acids is crucial in nutrition. A balanced diet must provide essential amino acids, which the body cannot synthesize, for building and repairing tissues, producing enzymes, and synthesizing hormones.
In clinical settings, protein levels (like albumin in the blood) are important indicators of nutritional status and liver function. Low protein levels can lead to conditions like edema.
What if? - If a patient has a genetic disorder like Phenylketonuria (PKU), they cannot metabolize the amino acid phenylalanine. This buildup is toxic to the brain. The treatment involves a strict diet low in phenylalanine, demonstrating the clinical importance of managing individual amino acids.

How to Approach the Question

First, identify the core subject of the question, which is 'proteins'.
Next, understand what 'basic structural units' means. This refers to the monomers or building blocks that make up a larger polymer.
Recall the four major types of biological macromolecules: carbohydrates, lipids, proteins, and nucleic acids.
Access your knowledge about the monomers for each macromolecule.
Evaluate the options: 'Fatty acids' are for lipids. 'Sucrose' is a carbohydrate. 'Amino acids' are the monomers of proteins. 'Peptides' are short chains of amino acids, not the single basic unit.
Select the option that correctly identifies the monomer for proteins.

Concept Tested & Keywords

QnQz41Cd7wGxAXhLewTIn6

E6 Physiology Ganong 27e Vol 1 Part 1 p. 26-28

E6 Textbook of Biochemistry for medical StudentsDM Vasudevan Part 1 (pp 26-370 of 370) pp. 93-95, 112-114