Welcome to Right Vita
 |
 |
 |
|---|---|---|
Neuro-Natural General |
Natural Energy |
Neuro Natural General |
Science has long established that many brain and nervous system disorders are a direct result of long-term nutrient deficiencies... |
The stresses of a modern life, natural depletion of essential nutrients from your diet, a decrease in your immunity and the subsequent vulnerability... |
The ‘standard’ medical solution for high cholesterol is to prescribe a statin drug. Whereas these are generally effective in lowering cholesterol… |
Structure of Vitamin A
As a bi-polar molecule vitamin A is set up by a long structure of the molecule of carbon and hydrogen form bi-polar covalent bonds between them. In fact, the structure of vitamin A contains a series of 5 conjugated C=C bonds (all-trans) which give a yellow color to the molecule. Vitamin A has a shape similar to retinoids which complete the vitamin sequence.
Retinoids can exist in various forms. Vitamin A derived from animal sources is in the form of an ester, which is retinyl palmitate in most cases. This is converted to an alcohol form (retinol) when the food passes through the small intestine. Retinal on the other hand is the existence of vitamin A in aldehyde form and retinoic acid is its acidic state. The retinol molecule is extremely similar to the vitamin A molecule in its structure.
Vitamin A can also be derived from plant sources which have what are known as precursors or provitamins of vitamin A. The carotenoid family of compounds is an example of precursors of vitamin A. It is easier to form the structure of vitamin A from retinoids than from provitamins since retinoids resemble the structure of vitamin A much more closely than provitamin A.
The beta-ionone ring is a distinct feature in all forms of vitamin A. An isoprenoid chain is always attached to the beta-ionone ring. This feature of the structure is essential for vitamin activity. The orange pigment of carrots is due to the presence of beta carotene, which can be represented in the form of 2 retinyl groups connected to each other. These contribute towards the maintenance of correct levels of vitamin A in the body. The retinyl group attaches to specific proteins and then becomes the primary light absorber that aids in the perception of light for proper vision. The name ‘retina’ is derived from the retinyl groups that facilitate the process of vision.
Vitamin A plays a very crucial role in the process of vision. Rods and cones found on the retina are known as rhodopsin and iodopsin respectively. 11-cis-retinal is bound to these rods and cones. When light enters the eye, the 11-cis-retinal gets converted to all-"trans" form through a process known as isomerization. This process sends a signal to the brain via the optic nerve. Then the process is reversed and the all-"trans"-retinal is converted back to the 11-"cis"-retinal form.