3. •Amino acid introduction
•Metabolism of amino acids
•Metabolic defects in amino acid metabolism
•Types of defects
•Disorders due to metabolic defects
•References
4. •Amino acids are biologically important organic
compounds containing amine (-NH2)
and carboxylic acid (-COOH) functional groups,
usually along with a side-chain specific to each
amino acid.
5. •Metabolism is the sum of the chemical processes and
inter conversions that take place in the cells and the
fluids of the body.
•This includes the absorption of nutrients and
minerals, the breakdown and buildup of large
molecules, the inter conversion of small molecules,
and the production of energy from these chemical
reactions
6. •Proteins are the most important and the most
abundant biomolecules in the human body.
•Amino acids may also serve as precursors to many
important substances for the body e.g.
neurotransmitters, biogenic amines, heme or purines
and pyrimidines and other nutrients carbohydrates
and lipids.
• Catabolism of their carbon skeletons covers
approximately 10-15 % of the energy requirements
of the body.
7. Three types
1. Defects in aromatic amino acids
2. Hereditary metabolic defects
3. Metabolic defects due to enzyme
deficiency
8. •Aromatic amino acids have benzene ring include
i. Phenylalanine ii. Tryptophan iii. Tyrosine
• Aromatic amino acids are component for the
production of neurotransmitters, including
epinephrine, nor epinephrine, and dopamine
melanin.
• Phenylalanine hydroxylase, tyrosine hydroxylase,
and tryptophan hydroxylase all require
tetrahydrobiopterin (BH4) as a cofactor.
9. •Defects caused by some inherited abnormality from
affected parents are termed as hereditary metabolic
defects.
•These defects can be due to some defective genes
which cause improper translation of genes.
•These defective genes can be inherited as autosomal
recessive and dominant disorders.
10.
11.
12. •Virtually every chemical step of metabolism is
catalyzed by an enzyme.
•Disorders of these enzymes that result from
abnormalities in their genes can be regarded as
defective metabolism due to enzymes.
•All the three types of defective metabolism can be
interrelated with each other.
So metabolism is very imp for the requirments of the bodys proper functioning. 20 basic proteinogenic amino acids inserted into protein molecules during the translation process.
Inborn errors of metabolism were first recognized by Sir Archibald Garrod, a British physician who noted in 1902 that the principles of Mendelian inheritance applied to certain examples of human metabolic variation. He perceived the genetic basis for a particular metabolic condition that leads to visible effects—alkaptonuria, which results in a black pigment in the urine. Since then, more advanced chemical methods have allowed the discovery of hundreds of enzyme defects that cause metabolic diseases.
The metabolism of aromatic amino acid is catalyzed by a small family of enzymes containing phenylalanine (PheH), tyrosine (TyrH), and tryptophan (TrpH) hydroxylase. defects lead to deficiencies of dopamine and serotonin within the central nervous system.
There are genes present in our genome that code for those proteins that have enzymatic functions for the degradation of amino acids. Autosomal disorders are more larger in no. then dominant one. Dominant is hawkinsinuria which is the inability to degrade the tyrosine.
A genetic condition that appears only in individuals who have two copies of an autosomal gene, one copy from each parent. The gene is on an autosome chromosome. The parents are carriers who have only one copy of the gene and do not exhibit the trait because the gene is recessive to its normal counterpart gene.
As already said aromatic enzymes require tetrahydrobiotin as cofactor .which may lead to enzyme defective metabolism.
