BIOCHEMISTRY I

CHAPTER V. VITAMIN

by

Sri Retno Dwi Ariani., S.Si., M.Si.NIP. 197112161998022004

E-MAIL ADRESS : edkostrad@yahoo.co.idHp. 081804476412

UNIVERSITY OF SEBELAS MARET SURAKARTA

20101

Definition of Vitamin

an organic compound required as a nutrient in tiny amounts by an organism

an organic chemical compound (or related set of compounds) is called a vitamin when it cannot be synthesized in sufficient quantities by an organism, and must be obtained from the diet.

2

Each vitamin has one or more specific purpose Vitamins are essential to life processes. Vitamins are generally used by the body with very

minimal changes Vitamins are usually required in only small amounts Most vitamins cannot be synthesized by the

body directly

Vitamins Characteristics

3

List of Vitamins

Year of discovery Vitamin Food source

1913 Vitamin A (Retinol) Cod liver oil, carrots

1910 Vitamin B1 (Thiamine) Rice bran

1920 Vitamin C (Ascorbic acid) Citrus, most fresh foods

1920 Vitamin D (Calciferol) Cod liver oil

1920 Vitamin B2 (Riboflavin) Meat, eggs

1922 Vitamin E (Tocopherol) Wheat germ oil, unrefined vegetable oils

1926 Vitamin B12 (Cobalamins) Liver, eggs, animal products

1929 Vitamin K (Phylloquinone/phytol naphthoquinone) Leafy green vegetables

1931 Vitamin B5 (Pantothenic acid) Meats, whole grains,in many foods

1931 Vitamin B7 (Biotin) Meats, dairy products, eggs

1934 Vitamin B6 (Pyridoxine) Meat, dairy products.

1936 Vitamin B3 (Niacin) Meat, eggs, grains

1941 Vitamin B9 (Folic acid) Leafy green vegetables 4

Classification of vitamins

a. Water Soluble are generally involved in the cellular metabolism of energy supplying nutrients. Characteristics :- usually contain hydrogen attached to electronegative atoms such as oxygen or nitrogen. - They easily form hydrogen bonds with water molecules- do not accumulate in the body, so regular supplies are necessary.example : Vitamin C, vitamin B1

b. Fat Soluble often have very specialized functions Characteristics :- have long nonpolar hydrocarbon chains or rings- usually accumulate in tissues and are not leached out quickly.- Common fat soluble vitamins include : A, D, E, K

5

Vitamin A (Retinol)

Structure :

Functions : a vitamin is needed by the retina of the eye in the form of a

spesific metabolite, the light-absorbing molekul retinal, and absolutely necessary for both scotopic and color vision.

as a irreversibly oxidized form of retinol knows as retinoic acid, which is an important hormone-like growth factor for epithelial and other cells

Sources: - commonly in cod liver oil, green vegetables, and fruit- carrots indirectly serve as a source of vitamin A since they

contain β- carotene which the body readily converts to vitamin A

6

Vitamin B1 (Thiamine)

Thiamine or thiamin or vitamin B1 (pronounced

/ˈθaɪ.əmɨn/ THYE-ə-min), and named as the "thio-vitamine"

("sulfur-containing vitamin") is a water-soluble vitamin of the

B complex. First named aneurin for the detrimental neurological effects of its lack in the diet, it was eventually assigned the

generic descriptor name vitamin B1. Its phosphate derivatives are

involved in many cellular processes. The best-characterized form is

thiamine pyrophosphate (TPP), a coenzyme in the catabolism of

sugars and amino acids. In yeast, TPP is also required in the first step of alcoholic fermentation.

Structure :

7

Vitamin C (Ascorbic acid)

Definition :Vitamin C or L-ascorbic acid or L-ascorbate is an essential nutrient for humans and certain other animal species, in which it functions as a vitamin.

Functions : 1. An antioxidant, 2. A cofactor in at least eight enzymatic reactions3. Especially important in wound-healing and in preventing

bleeding from capillaries

Structure :

8

Vitamin D

Functions :1. An important regulator of calcium metabolism. 2. It is involved in the uptake of calcium and

phosphate ions from food into the body. 3. It is necessary for the proper formation of bone

structures and teeth.

Structure of vitamin D

Sources :commonly found in fish liver oil as well as egg yokes

9

Characteristics : 1. an easily absorbed micronutrient with a key role in

maintaining health in humans and animals. 2. It is the central component of the cofactors FAD and

FMN, and is therefore required by all flavoproteins. 3. It required for a wide variety of cellular processes. 4. It plays a key role in energy metabolism, and for the

metabolism of fats, ketone bodies, carbohydrates, and proteins.

Structure :

Vitamin B2 (Riboflavin)

10

Vitamin E (Tocopherol)

Stucture :

Characteristic :1.a fat-soluble antioxidant that stops the production of reactive

oxygen species formed when fat undergoes oxidation.2.α-tocopherol (also written as alpha-tocopherol) has been most

studied as it has the highest bioavailability.

α-tocopherol the most important lipid-soluble antioxidant protects cell membranes from oxidation by reacting with lipid radicals produced in

the lipid peroxidation chain reaction.11

Vitamin K1 is also known as phylloquinone or phytomenadione (also called phytonadione).

Vitamin K2 (menaquinone, menatetrenone) is normally produced by bacteria in the large intestine, and dietary deficiency is extremely rare unless the intestines are heavily damaged, are unable to absorb the molecule, or are subject to decreased production by normal flora, as seen in broad spectrum antibiotic use.

Vitamin K

Functions :In the cells to convert glutamate in proteins to gamma-carboxyglutamate (gla)

Structure :

phylloquinone

menaquinone 12

Vitamin B5 (Panthotenic acid)

Structure : Also called panthotenate.

Characteristics :1. A water-soluble vitamin2. The amide between pantoate

and beta alanine.

Functions :For many animals an essential nutrient to synthesize coenzym-A (CoA)

and well as to synthesize and metabolize proteins,carbohydrate and fats.

For people an ingredient in some hair and skin care products.

Pantothenic acid are found in nearly every food, with high amounts in Whole-grain cereals, legumes, eggs, meat and royal jelly. 13

Vitamin B7 (Biotin)

Structure :

Definition :Biotin is a coenzym in the metabolism of fatty acids and leucine,

and it plays a role in gluconeogenesis.

Characteristics : a water-soluble B-complex vitamin (vitamin B7) that is composed of an ureido (tetrahydroimidizalone) ring fused with a tetrahydrothiophene ring. 14

Vitamine B6 (Pyridoxine)

Characteristics : 1. a water-soluble vitamin and is part of the vitamine B complex group2. Pyridoxal phosphate (PLP) is the active form and is a cofactor in many

reactions of amino acid metabolism, including transamination, deamination and decarboxylation. PLP also is necessary for the enzymatic reaction governing the release of glucose from glycogen.

7 forms of this vitamin are known :1. Pyridoxine (PN), is most commonly given as vitamine B6 supplement.2. Pyridoxine 5’phosphate (PNP)3. Pyridoxal (PL)4. Pyridoxal 5’-phosphate (PLP)5. Pyridoxamine (PM)6. Pyridoxamine 5’-phosphate (PMP)7. 4-Pyridoxic acid (PA), the catabolite which is excreted in the urine

15

Vitamine B3 (Niacin)

Definition : also known as vitamin B3, nicotinic acid and vitamin PP is an organic

Compound with the formula C6H5NO2 and, depending on the definition used, one of the forty to eighty essential human nutrients.

Characteristics :1. Colorless2. Water soluble solid is a derivative of pyridine, with a carboxyl group (COOH) at the 3-position

Niacin is one of five vitamins associated with a pandemic deficiency disease.

Structure :

16

Vitamin B9 (Folic acid)

Functions :1. is essential to numerous bodily functions ranging from nucleotide biosynthesis

to the remethylation of bomocystein.2. The human body needs folate to synthesize DNA, repair DNA, and methylate

DNA as well as to act as a cofactor in biological reactions involving folate3. especially important during periods of rapid cell division and growth. children

and adults both require folic acid in order to produce healthy red blood cells and prevent anemia

Structure :

17

Vitamine deficiency disease

No Vitamine deficiencies

Disease

1. A night blindness, xeropthalmia (most serious)

2. B1 beriberi

3. C scurvy

4. D rickets

5. B3 pellagra

18

Anti-vitamins are chemical compounds that inhibit the absorption

or actions of vitamins.

For example, avidin is a protein in egg whites that inhibits the

absorption of biotin.

Pyrithiamine is similar to thiamine (vitamine B1) and inhibits the

enzyms that use thiamine.

Anti vitamin

19

Thankyou

20