Keratin, the simple protein, is present in?

Appeared in: DSSSB - 28 August 2019 (Shift-1)

Explanation

Keratin is a fibrous structural protein that is the key component of hair, skin, and nails.
The image clearly shows fingernails, which are made of a tough, protective version of keratin called alpha-keratin.
Keratin provides mechanical strength and creates a protective barrier.
Among the given options, only nails are primarily composed of keratin.

Option A: The structural framework of the nose is made of bone and hyaline cartilage. Cartilage is a connective tissue rich in collagen and proteoglycans, not keratin.
Option B: The structural parts of the eye, such as the cornea and sclera, are composed mainly of collagen, which provides strength and transparency. Keratin is not a primary component of eye structures.
Option C: Ligaments are dense, fibrous connective tissues that connect bones to other bones. They are composed primarily of collagen fibers, which provide high tensile strength, and some elastin for flexibility. They do not contain keratin.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Presence of Keratin in Human Body Tissues as background academic context rather than a clinical decision trigger.
A nurse's assessment of a patient's hair, skin, and nails can provide important clues about their overall health, nutritional status, and potential underlying diseases.
For example, brittle nails can indicate nutritional deficiencies (like iron or biotin), thyroid problems, or fungal infections. Changes in nail appearance are important clinical signs.
What if? If the question asked for the most abundant protein in the human body, the answer would be collagen, which is a key component of connective tissues like ligaments, tendons, skin, and bones, not keratin.

How to Approach the Question

First, identify the core subject of the question, which is the protein 'keratin'.
This is a factual recall question based on basic anatomy and physiology.
Mentally or physically list the structures known to be composed of keratin. These are primarily the hair, the outer layer of the skin (epidermis), and nails.
Evaluate each option provided against this knowledge:
Nose: Is it made of keratin? No, it's mainly cartilage.
Eyes: Are they made of keratin? No, they are complex organs with structures made of collagen and other specialized tissues.

Concept Tested & Keywords

QnKNJvXzVy6Q4H1WOkpCtR

E6 Harper's Illustrated Biochemistry2023 (pp 26-793 of 813) p. 616-618

E6 Medicine Davidson Principles Practice 24e p. 1232-1234

E6 Anatomy Grays 43e Vol 1 Part 1 p. 42-44

Practise the full DSSSB - 28 August 2019 (Shift-1)

Attempt every question from this paper in a timed mock, then review the full solution for each one.