What is the approximate UV absorption maximum (λmax) for tyrosine?
274.6 nm accurately defines or describes the concept asked in this question. Within Amino Acids Basics, precise definitions and terminology are essential for clear scientific communication. The other options (257.4 nm, 279.8 nm, and 300 nm) either describe related but distinct concepts, use incorrect terminology, or confuse similar-sounding terms that have different scientific meanings. A thorough understanding of exact definitions helps distinguish between closely related biological concepts and is crucial for competitive examinations.
Ref: Lehninger Principles of Biochemistry, Nelson & Cox, 8th Ed., Ch. 3