Download Co-enzyme derived from vitamin and their role in metabolic action

Co-enzyme derived from vitamin and their role in metabolic action
(vit,B1, B2 B3, B5, B6)
•
•
•
•
•
LEARNING OBJECTIVES
By the end of the lecture the students should be able to:List vitamin B- complex
Study biological active co- enzyme
Study the metabolic role of coenzyme derived from vitamin B complex
INTRODUCTION
Vitamins are substances needed in small amounts for normal body
functions that the body cannot synthesize in adequate amounts.
•
In many cases vitamins act as cofactors that are needed in order to
allow enzymes to perform their important work of facilitating metabolism
in the body.
•
In this case the vitamins are called coenzyme vitamins.
•
Coenzyme vitamins and direct precursors of coenzyme vitamins are
found in foods in relatively small, but significant amounts.
The B Complex family of vitamins:
•
The following are list of coenzyme vitamins:
Vitamin B1 in the form of thiamin diphosphate (or cocarboxylase)
•
Vitamin B2 in the form of riboflavin 5’-phosphate sometimes called
flavinmononucleotide (FMN)
•
Vitamin B3 in the forms of forms of niacinamide (partial coenzyme),
nicotinamide diphosphate (NAD), and nicotinamide diphosphate
hydrate (NADH)
•
Vitamin B5 in the form of panthetine
•
Vitamin B6 in the form of pyridoxal 5’-phosphate
•
Folate in the forms of folic acid (5-formyl tetrahydrofolate) and
methyltetrahydro folate
Thiamine
•
Thiamine or thiamin or vitamin named as the "thio-vitamine"B1is a
water-soluble vitamin of the B complex.
•
First named aneurin for the neurological effects if not present in the
diet, it was eventually assigned the generic descriptor name vitamin B1.
•
Its phosphate derivatives are involved in many cellular processes.
•
Thiamine pyrophosphate (TPP), a coenzyme in the catabolism of
sugars and amino acids.
•
Thiamine is used in the biosynthesis of the neurotransmitter
•
Thiamine is mainly the transport form of the vitamin, while the active
forms are phosphorylated thiamine derivatives.
•
There are five known natural thiamine phosphate derivatives:-
•
Thiamine monophosphate (ThMP),
•
Thiamine diphosphate (ThDP), also sometimes called thiamine
pyrophosphate (TPP),
•
Thiamine triphosphate (ThTP),
•
Recently discovered adenosine thiamine triphosphate (AThTP),
•
Adenosine thiamine diphosphate (AThDP).
•
•
vitamin B- 2 RIBOFLAVIN
Riboflavin fulfills its role in metabolism as the coenzymes flavin
mononucleotide (FMN) and flavin adenine dinucleotide (FAD).
FMN is formed by ATP-dependent phosphorylation of riboflavin,
whereas FAD is synthesized by further reaction of FMN with ATP in
which its AMP moiety is transferred to the FMN.
NIACIN VITAMIN B- 3
•
Nicotinic acid, nicotinamid, and tryptophan are co-factors for
nicotinamide adenine dinucleotide (NAD) and nicotinamide adenine
dinucleotide phosphate (NADP).
•
NADP and NAD are coenzyme for many dehydrogenases, participating
in many hydrogen transfer processes.
•
NAD is important in catabolism of fat, carbohydrate, protein and alcohol
PANTOTHENIC ACID VITAMIN B- 5
•
pantothenic acid is require to synthesize coenzyme-A (CoA), as well as
to synthesize and metabolize proteins, carbohydrates, and fats.
•
Pantothenic acid is used in the synthesis of coenzyme A (CoA).
•
CoA is important in energy metabolism for pyruvate to enter the
tricarboxylic acid cycle (TCA cycle) as acetyl-CoA, and for
α-ketoglutarate to be transformed to succinyl-CoA in the cycle.
•
VITAMIN B6 PYRIDOXAL PHOSPHATE
Several forms of the vitamin are known, but pyridoxal phosphate (PLP)
is the active form and is a cofactor in many reactions of amino acid
metabolism,
including
transamination,
deamination,
and
decarboxylation.
•
The primary role of vitamin B6 is to act as a coenzyme to many other
enzymes in the body that are involved predominantly in metabolism.
•
This role is performed by the active form, pyridoxal phosphate.
•
This active form is converted from the other natural forms founds in food
pyridoxal, pyridoxine and pyridoxamine.
•
Vitamin B6 is involved in the following metabolic processes:
•
•
•
•
•
amino acid, glucose and lipid metabolism
neurotransmitter synthesis
histamine synthesis
hemoglobin synthesis and function
gene expression
REFERENCE
•
Harper’s Biochemistry
-----------------------------------------------------------------------------------------------------------------------------