Match the following amino acids with their respective derivatives:

Substance Derivative

A. Tyrosine 1. Thyroid hormone

B. Tryptophan 2. Melatonin

C. Glycine 3. Taurine

D. Cysteine 4. Creatine Options:

1. A

   A-1, B-2, C-3, D-4

2. B

   A-1, B-2, C-4, D-3

3. C

   A-2, B-1, C-4, D-3

4. D

   A-2, B-1, C-3, D-4

Appeared in: INI-CET EXAM -2025

Explanation

• Tyrosine is iodinated to form thyroxine (T4) and triiodothyronine (T3), which are the primary thyroid hormones essential for regulating metabolism.
• Tryptophan serves as the precursor for the synthesis of serotonin, which is then converted to melatonin in the pineal gland.
• Glycine, along with arginine and methionine, participates in the biosynthesis of creatine, a crucial molecule for energy storage in muscles as creatine phosphate.
• Cysteine is converted to taurine, which is important for conjugating bile acids to form salts like taurocholic acid, aiding in fat digestion.

Why Other Options Were Wrong

• Option A: This option incorrectly pairs Glycine with Taurine (C-3) and Cysteine with Creatine (D-4). The correct pairings are Glycine with Creatine (C-4) and Cysteine with Taurine (D-3).
• Option C: This option incorrectly pairs Tyrosine with Melatonin (A-2) and Tryptophan with Thyroid hormone (B-1). Tyrosine is the precursor for thyroid hormones, and Tryptophan is the precursor for melatonin.
• Option D: This option contains multiple incorrect pairings. It incorrectly matches Tyrosine with Melatonin (A-2), Tryptophan with Thyroid hormone (B-1), Glycine with Taurine (C-3), and Cysteine with Creatine (D-4).

Related Visual

• Visual 1: Diagram - A biochemical flowchart showing the pathway from Tyrosine to Thyroid hormones (T3 and T4). This helps visualize the synthesis process.
• Visual 2: Diagram - A pathway illustrating the conversion of Tryptophan to Serotonin and then to Melatonin. This clarifies the two-step process.
• Visual 3: Diagram - A flowchart depicting the synthesis of Creatine, showing the involvement of Glycine, Arginine, and Methionine. This highlights the multi-amino acid contribution.
• Visual 4: Diagram - The metabolic conversion of Cysteine to Taurine, emphasizing its role in forming bile salts.

Clinical Relevance

• Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Metabolism of amino acids and their conversion to specialized products as background academic context rather than a clinical decision trigger.
• Understanding these pathways is crucial for diagnosing and managing metabolic disorders. For example, a deficiency in thyroid hormone production from tyrosine leads to hypothyroidism, requiring hormone replacement therapy.
• Melatonin, derived from tryptophan, is used clinically to treat sleep disorders like insomnia and jet lag. Its synthesis is linked to the body's light-dark cycle.
• Creatine, synthesized from glycine, is a popular supplement for athletes to improve performance and muscle mass. Serum creatinine levels are a key indicator of renal function, as creatinine is the breakdown product of creatine.

How to Approach the Question

• First, identify the core task of the question, which is to match each amino acid in Column A with its correct derivative in Column B.
• Scan the pairs and try to identify one or two matches you are confident about. For example, the link between Tryptophan and Melatonin (for sleep) is a common piece of knowledge.
• Use this known pair (B-2) to eliminate options that do not contain it. In this case, options C and D are eliminated, leaving A and B.
• Next, try to recall another pair. The connection between Tyrosine and Thyroid hormone (A-1) is also fundamental. Both remaining options (A and B) have this pair.
• The deciding factor is the pairing for Glycine and Cysteine. Recall that Glycine is a component of Creatine (C-4), and Cysteine is a precursor to Taurine (D-3).
• Select the option that contains all the correct pairings: A-1, B-2, C-4, D-3.

Concept Tested & Keywords

• Concept Tested: Metabolism of amino acids and their conversion to specialized products.
• Stem keywords: amino acids, derivatives, Tyrosine, Tryptophan, Glycine, Cysteine
• Lead-in keywords: Match

Question ID

QXnAR-QiZJ5rJncbuWA8Gs

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