In 1931, a chemist named Arthur Fox was pouring some powdered PTC (phenylthiocarbamide) into a bottle when some of the powder accidentally blew into the air. A colleague standing nearby complained that the dust tasted bitter. Fox tasted nothing at all. Curious how they could be tasting the chemical differently, they tasted it again. The results were the same. Fox had his friends and family try the chemical then describe how it tasted. Some people tasted nothing. Some found it intensely bitter, and still others thought it tasted only slightly bitter (from The University of Utah Genetic Science Learning Center, 2013). It is estimated that 70% of the population can taste PTC and 30% cannot. We also know that the ability to taste PTC is passed from parent to child.
Which of the following molecules is responsible for the fact that parents who can taste PTC will most often have children who can taste PTC?
A. Nucleic Acids
B. Proteins
C. Carbohydrates
D. Lipids
B. Proteins
To determine which molecule is responsible for the fact that parents who can taste PTC (phenylthiocarbamide) will most often have children who can taste PTC, we need to understand the inheritance of traits. The ability to taste PTC is known to be passed from parent to child, which suggests an underlying genetic basis.
Genes, which are segments of DNA, carry the instructions for producing proteins. Proteins play a vital role in many biological processes, including the development and function of taste receptors. Therefore, the molecule responsible for the ability to taste PTC is likely to be proteins.
So, the correct answer is B. Proteins.