Vitamins Flashcards
Where are lipid soluble vitamins stored?
In body lipids
Define what is meant by a vitamin.
Organic compounds which are required for the maintenance of normal health and metabolic activity. They cannot be synthesised in the body and must be provided in the diet but they are required in very small amounts.
What do lipid soluble vitamins require in order to be absorbed or transported?
Bile salts
Where are vitamin A & D stored?
In the liver.
Where are water soluble vitamins stored?
They are not usually stored (except vitamin b12). Storage only occurs if they are bound to enzymes or storage proteins.
Name 8 water soluble vitamins
Thiamin (B1) Riboflavin (B2) Niacin Pantothenic acid B6 Biotin Folate B12
Name four lipid soluble vitamins
Vitamin A
Vitamin D
Vitamin E
Vitamin K
What are coenzymes?
Organic molecules required by certain enzymes to carry out catalysis. They bind to the active site of the enzyme and often function as intermediate carriers of electrons or functional groups.
What foods can thiamin (B1) be found in?
Both animal and vegetable foods: pork, vegetables, milk, cheese, fresh and dried fruits, eggs, wholegrain breads and some fortified cereals.
What is the coenzyme for thiamin (B1)?
Thiamine pyrophosphate (TPP)
Thiamine pyrophosphate which is the coenzyme for thiamin is used in which important reactions?
Pyruvate dehydrogenase: conversion of pyruvate to acetyl coA (enters TCA cycle)
Alpha-ketoglutarate dehydrogenase: conversion of intermediate alpha-ketoglutarate to succinyl coA
Which foods is riboflavin found in?
Foods of animal origin: milk & dairy, eggs, meat, fish
In which type of reactions is riboflavin coenzymes used?
Oxidation reductions reactions including: electron transport and fatty acid synthesis and oxidation
