Metabolism is the process by which a living organism takes energy from its surroundings and uses it to sustain itself, develop, and grow. In humans, from the age of 25 onward, the "metabolic rate slows down 5-10% each decade."
- Wile, Dr. Jay L. Exploring Creation With General Science. Anderson: Apologia Educational Ministries, Inc. 2000
- 18 Ways To Boost Metabolism, Energy And Weight Loss. Retrieved on 3 November 2014. “Unfortunately, starting at the age of 25, without proper diet and exercise, our metabolic rate slows down 5-10% each decade.”
- Oleson, Lauren (2008). Investigation of the Inter-individual Variability in Human Cytochrome P450 3A Metabolism. ProQuest. ISBN 9780549764342. Retrieved on 3 November 2014. “Phase I reactions involve either the introduction or exposure of a more polar functional group. These reactions can include oxidation, reduction, and hydrolysis. Phase II conjugation reactions on the other hand, involve the covalent linkage of a functional group on the parent drug compound and a polar compound such as glucuronic acid.”