Derivative dynamics

"The derivative of the quotient of two differentiable functions equal the denominator times the derivative of the numerator minus the numerator times the derivative of the denominator, all divided by the square of the denominator."
Washington, Allyn J. "Basic Technical Mathematics with Calculus." p.672. Chapter 23. The Derivative.

Does Chitin have UV protection properties?

Whilst considering the evolutionary advantage of Chitin, the exoskeleton of Arachnids and membrane of fungi, and it's benefits in an environment of high UV, prior to a substantial Ozone thickness; I was wondering if Chitin did in fact have UV protection factors?

Adenine Obsession?

What is it about Adenine (A) H3N5C5 (approx. AMU = 133.1137), a double ringed purine with 2 hydrogen bonds, that seems to pop up everywhere in my Life Science studies? I found it in DNA, RNA, NAD+, CoEnzyme A, FAD+ and ever ATP!