Vitamin A
Tinye obere oge
Vitamin A gụnyere vitamin A1 na A2. Vitamin A1 na A2 yiri onwe ha n'ụdị ha) Enwere ike iji beta-carotene sitere na osisi mepụta Retinol. N'okpuru catalysis nke β-carotene-15, 15'-peroxide (bioxygenase) n'ime ahụ, enwere ike ịgbanwe β-carotene ka ọ bụrụ molekul abụọ nke retinaldehyde (ratinal), na retinaldehyde na reductase. A na-ebelata ya ka ọ bụrụ retinol n'okpuru ọrụ nke. Ya mere, a makwaara beta-carotene dị ka vitamin A.
Njirimara kemịkalụ
Vitamin A bụ ntụ ntụ kristal ma ọ bụ kristal odo na-acha uhie uhie, nke na-anaghị agbaze na mmiri na glycerin, a na-agbazekwa ya n'ọtụtụ ihe ndị na-agbaze ihe ndị dị ndụ dịka alcohols, ethers, hydrocarbons na halogenated hydrocarbons. Aha kemịkalụ nke ahụ vitamin A - retinol bụ all-trance 3,7-dimethyl-9-(2,6,6-trimethyl-1-cyclohexene-1)-2,4,6,8-nontetraene-1-ol, nwere njikọ abụọ anọ a na-ejikọta ọnụ na agbụ akụkụ ya.
Ọrụ na mmetụta nke anụ ahụ
Vitamin A bụ vitamin na-agbaze abụba, ọrụ ya dịkwa n'ụdị retinoic acid. Carotene bụ isi iyi dị mkpa nke vitamin A. Vitamin A kachasị arụ ọrụ na carotene bụ beta-carotene. Ọnụego mmịpụta n'ime eriri afọ mmadụ bụ ihe dị ka otu ụzọ n'ụzọ isii nke vitamin A. A na-echekwa Vitamin A n'ime imeju n'ime ahụ, ihe dị ka 90% ruo 95% nke mkpokọta ahụ, a na-echekwa obere ego na anụ ahụ adipose. Vitamin A na-arụ ọrụ dị oke mkpa na ọrụ metabolic nke ahụ mmadụ.
