in this ppt you will be able to know more about the role of vit A in the vision in the dim light and more about .

1. All trans retinal
Retinal reductase
All trans retinol
Closure of Na+ channels of outer segment
Intracellular potential becomes more –ve
(hyperpolarization)
Initiation nerve impulse from receptors of retina to optic nerve to brain
Biochemistry of special sense
modules MEQ
BY/Mohamed Ali
Dr /Mohamed Ali

2. Rhodopsin Bathorhodopsin
Light energy
Lumirhodopsin
Metarhodopsin 1
Metarhodopsin 2
All trans retinal
Opsin
Retinal reductase
All trans retinol
In liver
Isomerase
11-cis retinol
Retinal oxidase
11-cis retinal
Activation of transducin
Activation of c-GMP phosphodiesterase
Hydrolysis of c-GMP → ↓ c-GMP & ↑ GMP
Closure of Na+ channels of outer segment
Intracellular potential becomes more –ve
(hyperpolarization)
Initiation nerve impulse from receptors of retina to optic nerve to brain
Explain role of vitamin A in vision
Visual cycle
MEQ
By/ Mohamed Ali