BIOMOLECULES AND ENZYMES

Detailed explanation-1: -The two main forms of vitamin A in the human diet are preformed vitamin A (retinol, retinyl esters), and provitamin A carotenoids such as beta-carotene that are converted to retinol. Preformed vitamin A comes from animal products, fortified foods, and vitamin supplements. Carotenoids are found naturally in plant foods.

Detailed explanation-2: -Vitamin A (retinol, retinoic acid) is a nutrient important to vision, growth, cell division, reproduction and immunity. Vitamin A also has antioxidant properties.

Detailed explanation-3: -Beta-carotene is an antioxidant. Antioxidants protect cells from damage caused by substances called free radicals. Free radicals are believed to: Contribute to certain long-term diseases.

Detailed explanation-4: -Recent evidence has shown vitamin A, carotenoids and provitamin A carotenoids can be effective antioxidants for inhibiting the development of heart disease. Vitamin A must be obtained from the diet: green and yellow vegetables, dairy products, fruits and organ meats are some of the richest sources.

Detailed explanation-5: -Retinol is a type of retinoid found in vitamin A. Vitamin A is composed of two parts: retinoids, which include retinol, and carotenoids which inckude beta-carotine. Retinol is a type of vitamin A found in animal products like liver, kidney, eggs, and dairy products.