Question

For some proteins, small molecules are integral to their structure and function. Enzymes can synthesize some of these small molecules, whereas others, called vitamins, must be ingested in the food we eat. Which of the following molecules is not classified as a vitamin but does require the ingestion of a vitamin for its production?

(a) retinal
(b) biotin
(c) zinc
(d) heme

Answer 1

Heme is not a vitamin but requires vitamin B6 for synthesis. Vitamins, which function as coenzymes, along with minerals, as cofactors, are essential nutrients that the body often needs to obtain through dietary intake, including some amino acids that cannot be synthesized.

Step-by-step explanation:

The molecule that is not classified as a vitamin but does require the ingestion of a vitamin for its production is (d) heme. While retinal, biotin, and zinc have their own roles and properties, heme is a component of hemoglobin, which requires vitamin B6 (pyridoxine) for its synthesis. Vitamins are organic compounds required in small quantities for our body's proper functioning and are mostly obtained through diet as they are essential nutrients. They function as coenzymes and are vital for many enzymes to work effectually. Several vitamins, like vitamin D and vitamin B7 (biotin), can be synthesized by the body under certain conditions, but most need to be ingested through food. Minerals like zinc are considered cofactors and are also essential but inorganic nutrients that must be sourced from food. The human body can synthesize only 11 of the 20 required amino acids; the rest, termed 'essential amino acids', also must be obtained from food.