Amino acids are the building blocks of protein. Proteins are long chains of amino acids. Your body has thousands of different proteins that each have important jobs. Each protein has its own sequence of amino acids. The sequence makes the protein take different shapes and have different functions in your body.22-Dec-2021

1. AMIN
O
ACID

2. Specific Learning Objectives
At the end of the lecture, student should be able to:
1. State formula for amino acid
2. Classify amino acids based on Nutrition
3. Classify amino acid based on metabolic fate
4. Enlist properties of amino acid
5. Enumerate function of amino acid
6. Describe Digestion and absorption of protein
7. Explain metabolism of amino acid

3. Introduction
• Amino acids are the building block of protein
• Amino acids are the basic structural units of proteins
• Amino acids are the most essential component of all
living cell
• More than 300 amino acids are found in nature
• Only 22 amino acids are present in protein

4. The Anatomy of an
Amino Acid

5. • R
 H
 COOH-Carboxyl (acidic)
 NH2-amino (Basic)
• Amino acids are group of organic compounds
containing two functional group-amino (-NH2)
and carboxyl (-COOH)
Amino acids possess four
distinct group-

6. CLASSIFICATION OF
AMINO ACID
Essential Nonessential
Conditionally
essential

7. Classification of amino acids
Essential amino acids (Indispensable)
– These are not synthesized in our body so must be
consumed in the diet
Nonessential (Dispensable)
– can be synthesized in the body
Conditionally essential – cannot be synthesized due
to illness or lack of necessary precursors
• Premature infants lack sufficient enzymes needed to
create arginine, Histidine

10. Properties of amino acids
Physical properties
Soluble in water and insoluble in organic solvent
Melt at 200 degree C
Amino acid may have sweet, bitter or salty so used as
a flavouring agent in food industry
All are optically active except glycine
it can act as acid or base

11. Chemical properties
Decarboxylation -formation of amine from amino acid
e.g. Histamine from histadine
Amide formation-aspartic acid from Asparagine and
glutamic acid from Glutamine
Salt and ester formation-
Transeamination- transfer of amino group
Deamination- removal of amino group

12. Cont …
• Formation of carbamino compound
• Peptide bond formation
• Transmethylation- transefer of methyl group
• Peptide bond formation

15. Functions of amino acids
• Synthesis of variety of protein
• It act as a building block of protein
• Required to maintain proper nitrogen balance
• Required to maintain proper health
• Role in covalent modification of enzymes & enzyme
catalysis

16. Functions of amino acids
• Specific amino acids give rise to specialized product
e.g.
 Tyrosine forms T3, T4 hormone, melanin
 Tryptophan synthesize Niacin
 Glycine, argenine, methionine synthesize creatinine
 Glycine and cysteine help in synthesis of bile salt
 Histadine synthesiz histamine

17.  Neurotransmitters eg GABA, dopamine, serotonin &
histamine
 Synthesis of purines & pyrimidines
 Synthesis of urea & creatinine
 Glycine synthesis of heme

18. Amino Acid Absorption
• Amino acids are absorbed in the small intestine
• Amino acids are transported to the liver from the
intestines via the portal vein
• In the liver, amino acids are
• Used to synthesize new proteins
• Converted to energy, glucose, or fat
• Released to the bloodstream and transported to cells
throughout the body

19. Cont..
• The nitrogenous part used in synthesis of nitrogenous
substance such as creatine, glutathione, purines, pyrimidine,
amino sugar, ammonia, urea

20. Amino Acid Metabolism
• Liver metabolizes amino acids, depending on bodily
needs
• Most amino acids are sent into the blood to be picked up
and used by the cells
• Amino acid pool is limited but has many uses
• Protein turnover – the continual degradation and
synthesizing of protein

22. Metabolic Fate of Amino Acids
Figure 6.7

24. NH3
Amino acid--------Carbon skeleton-----Acetyl CoA

26. Expected Question
Essay/ Situation Question
• Describe amino acid with regards to definition,
structure, classification and its properties
• Explain the metabolism of amino acids.
Short Question
• Explain function of amino acid

27. THANK YOU