Question

The human eye contains a molecule called 11-cis-retinal that changes conformation when struck with light of sufficient energy. The change in conformation triggers a series of events that results in an electrical signal being sent to the brain. The minimum energy required to change the conformation of 11-cis-retinal within the eye is about 164 {\rm kJ}/{\rm mol}.Calculate the longest wavelength visible to the human eye.

Answer 1

Answer:

1.21 × 10⁻³⁰ m

Explanation:

164 kJ of energy (E) are required to change the conformation of 1 mole of 11-cis-retinal. The wavelength (λ) of the radiation having such energy can be calculated through the Planck-Einstein equation.

E = h . ν = h . c . λ⁻¹

where,

h is the Planck constant

ν is the frequency

c is the speed of light

λ is the wavelength

$\lambda=\frac{h.c}{E} =\frac{6.63 \times 10^{-34}J.s \times 3.00 \times 10^{8} m/s }{164 \times 10^{3} J } =1.21 \times 10^{-30} m$