FNDH 620 - Final Exam Study Guide

FNDH 620 - Final Exam Study Guide True or False Vitamins: - cannot be made in the body - noncaloric - required in small amounts (mg and mcg) - TRUE Vitamins: - cannot be made in the body - noncaloric - required in small amounts (mg and mcg) What 3 forms can vitamin A take? - - retinol (alcohol) - retinal (aldehyde) - retinoic acid (acid form from retinal) What form of vitamin A is normally found in blood and tissues? - Retinyl Palmitate What form of vitamin A is found in plants? - Previtamin A - carotenoid structure that includes the carotenes and xanthophylls - found in plants - needs to be converted to active vitamin A What is the most potent form of vitamin A? - Beta carotene Where can retinyl esters be found? - Animal Products *only* Where can vitamin A be found? - Fortified milk and milk products Where can previtamin A carotenoids be found? - Plant sources - orange and dark green vegetables Vitamin A containing micelles form and traverse the enterocyte plasma membrane by what type of diffusion? - Passive Diffusion What two things are needed in the digestion of vitamin A? - Bile and Fat Beta-carotene and other carotenoids can be converted to retinol by what means? - Beta- carotene and other carotenoids can be converted to retinol by cleavage of the central double bond When beta-carotene is cleaved, how many molecules of retinal does it make? - 1 beta- carotene = 2 retinal Retinyl, retinyl esters, and carotenoids are packaged into what and transported where? - Retinyl, retinyl esters, and carotenoids are packaged in *chylomicrons* and transported in the *lymphatic system*. Vitamin A and carotenoids are metabolized where and as what? - Vitamin A and carotenoids are metabolized in the liver as chylomicron remnants. Retinoic acid is absorbed and transported to which organ bound to what protein? - Retinoic acid is absorbed and transported to the liver bound to albumin. The liver stores 90% of which vitamin? - vitamin A What are the functions of vitamin A & Carotenoids?