Problem:
Question 1: How can artificial tastes and smells produce the sensation of their natural counterparts? Please explain.
Question 2: Which of the following structural motifs are NOT commonly found in the DNA-binding motifs of proteins that act as transcriptional regulators?
A) Homeodomain
B) Helix-turn-helix
C) Leucine Zipper
D) Beta-barrel
Please select correct answer and also provide explaination.