Answer:
Answer is glucose.
Explanation:
Glucose is very important to the yeast cell. Because, it is known to be the energy and carbon source to the yeast cell.
Apart from the importance mentioned, the glucose also act as a signaling molecule.This means that , it can regulate the physiology aspects of the yeast cell.
It should be noted that, a signaling molecule can be described as a molecule capable of transmitting information between or among the cells.