Question

Different forms of Vitamin A are: A. Retinal (Vitamin A aldehyde) B. Retinyl Palmitate (Vitamin A acid) C. Retinol (Vitamin A alcohol) D. Retinyl ester (Vitamin A ester) E. $\beta$-carotene (provitamin A) Choose the correct answer from the options given below:

• A. A and E only \
• B. A, C and E only \
• C. C and E only \
• D. B, D and E only

Hint:

Retin-OL = Alcoh-OL, Retin-AL = Aldehyde. Carotene is the precursor found in carrots (Provitamin A).

Answer 1

The Correct Option is B

Step 1: Concept Vitamin A belongs to a class of fat-soluble organic retinoid compounds that exist in distinct functional oxidation states and precursor structures.

Step 2: Meaning * Suffixes matching organic chemistry structures: "-ol" indicates an alcohol, "-al" indicates an aldehyde, and "-oic acid" indicates a carboxylic acid.

Step 3: Analysis * Statement A: Retinal is indeed the aldehyde form of Vitamin A, crucial for biochemical visual cycles $\rightarrow$ Correct. * Statement B: Retinyl palmitate is a storage ester form, not a free acid form (Retinoic acid is the true Vitamin A acid) $\rightarrow$ Incorrect. * Statement C: Retinol is the primary transport form and acts as the pure alcohol state of Vitamin A $\rightarrow$ Correct. * Statement D: Retinyl ester is a broad storage class rather than a specific chemical form of Vitamin A itself $\rightarrow$ Incorrect. * Statement E: $\beta$-carotene is a plant hydrocarbon carotenoid that undergoes cleavage to form two molecules of retinal, making it a classic provitamin A compound $\rightarrow$ Correct.

Step 4: Conclusion The chemically accurate options are A, C, and E, corresponding to option B. Final Answer: (B)