Aperson who sprints for 45 seconds obtains most of his or her energy from

Answer; 
A person who sprints for 45 seconds obtains most of his or her energy from muscle glycogen.

Explanation; 
Muscle glycogen is the glycogen that is stored in the muscles and liver.
Glycogen is the primary source of energy during exercise, and low glycogen levels decreases the ability to gain strength and muscle. An athlete who sprints for 45 seconds obtains most of his or her energy from the muscle glycogen. 

Some of her  assignments would be creation of drugs. she is a medical chemist after all so she'd need to have the necessary knowledge to make medicine which can later be sold in a pharmacy