BIOMOLECULES AND ENZYMES

Detailed explanation-1: -The absorption maxima of the Pr and Pfr forms of plant phytochromes are near 670 nm and 730 nm, respectively (Table 1).

Detailed explanation-2: -(A) Absorption spectra of the two forms (Pr and Pfr) of phytochromes. The Pr form absorbs maximally at 660 nm, while the Pfr form absorbs maximally at 730 nm. (B) Dual roles (sensory and regulatory) of the phytochrome molecules.

Detailed explanation-3: -Phytochromes have two photo-interconvertible forms: Pr and Pfr. Pr absorbs red light ( 667 nm) and is immediately converted to Pfr. Pfr absorbs far-red light ( 730 nm) and is quickly converted back to Pr.

Detailed explanation-4: -Phytochromes are red-light photoreceptors that undergo reversible photoconversion between a red-light-absorbing state (Pr) and a far-red-light-absorbing state (Pfr), and thereby they regulate a wide range of physiological responses in plants, fungi, and photosynthetic bacteria (1–5).

Detailed explanation-5: -Phytochromes are the light sensitive pigments that set the circadian rhythms based on the length of night. Phytochromes have two inter convertible forms Pr and Pfr. Absorption of red light (667nm) immediately converts the Pr into Pfr while absorption of far red light (730 nm) converts the Pfr into Pr form.