This document provides information about amino acids. It defines amino acids as organic compounds that combine to form proteins, which are the building blocks of life. Amino acids are classified into three groups: essential amino acids which cannot be made by the body and must come from food, nonessential amino acids which the body can produce, and conditional amino acids. It then provides details about the structure, properties, and classification of various individual amino acids like lysine, histidine, phenylalanine, and tryptophan.

1. Presented by:
Mrunmayee S. Khardikar
STD : XI[ SCIENCE]
BIOLOGY
AMINO ACIDS
Presented to :
Mr. Kailash Vilegave Sir

2. BIOLOGY
AMINO ACIDS

3. DEFINE AMINO ACIDE
 Amino acids are organic compounds that combine to form proteins. Amino acids and
proteins are the building blocks of life.
 When proteins are digested or broken down, amino acids are left. The human body
uses amino acids to make proteins to help the body:
 Break down food
 Grow
 Repair body tissue
 Perform many other body functions

4. List of Amino Acids

5. CLASSIFICATION :
 Amino acids are classified into three groups:
 Essential amino acids
 Nonessential amino acids
 Conditional amino acids

6. Essential amino acids
Essential amino acids
 Essential amino acids cannot be made by
the body. As a result, they must come
from food.
 The 9 essential amino acids are: histidine,
isoleucine, leucine, lysine, methionine,
phenylalanine, threonine, tryptophan, and
valine.
Diagram

7. Non essential amino acids
Non essential amino acid
 Nonessential means that our bodies
produce an amino acid, even if we do not
get it from the food we eat. Nonessential
amino acids include: alanine, arginine,
asparagine, aspartic acid, cysteine,
glutamic acid, glutamine, glycine, proline,
serine, and tyrosine.
Diagram :

8. Lysine
 Lysine is an α-amino acid that is used in the biosynthesis of proteins. It contains an
α-amino group, an α-carboxylic acid group, and a side chain lysyl, classifying it as
a basic, charged, aliphatic amino acid. It is encoded by the codons AAA and AAG.
 Formula: C6H14N2O2
 Molar mass: 146.19 g/mol
 IUPAC ID: Lysine
 Structure and properties: Refractive index (n), Dielectric constant (εr), etc
 Soluble in: Water
 Classification: Amino Acid

9. HISTIDINE
 Histidine is an α-amino acid that is used in the biosynthesis of proteins. It contains
an α-amino group, a carboxylic acid group, and an imidazole side chain,
classifying it as a positively charged amino acid at physiological pH.
 Molar mass: 155.1546 g/mol
 Formula: C6H9N3O2
 Structure and properties: Refractive index (n), Dielectric constant (εr), etc
 Classification: Amino Acid

10. PHENYLALANINE
 Phenylalanine is an essential α-amino acid with the formula C ₉H ₁₁NO ₂. It can be
viewed as a benzyl group substituted for the methyl group of alanine, or a phenyl
group in place of a terminal hydrogen of alanine.
 Formula: C9H11NO2
 Molar mass: 165.19 g/mol
 IUPAC ID: Phenylalanine
 Acidity (pKa): 1.83 (carboxyl), 9.13 (amino)
 Structure and properties: Refractive index (n), Dielectric constant (εr), etc
 Classification: Essential amino acid

11. TRYPTOPHAN
 Tryptophan is an α-amino acid that is used in the biosynthesis of proteins.
Tryptophan contains an α-amino group, an α-carboxylic acid group, and a side
chain indole, making it a non-polar aromatic amino acid. It is essential in humans,
meaning that the body cannot synthesize it and it must be obtained from the diet.
 Formula: C11H12N2O2
 Molar mass: 204.23 g/mol
 IUPAC ID: Tryptophan or (2S)-2-amino-3-(1H-indol-3-yl)propanoic acid
 Acidity (pKa): 2.38 (carboxyl), 9.39 (amino)
 Structure and properties: Refractive index (n), Dielectric constant (εr), etc

12. LEUCINE
 Leucine is an essential amino acid that is used in the biosynthesis of proteins.
Leucine is an α-amino acid, meaning it contains an α-amino group, an α-
carboxylic acid group, and a side chain isobutyl group, making it a non-polar
aliphatic amino acid.
 Formula: C6H13NO2
 Molar mass: 131.17 g/mol
 IUPAC ID: Leucine
 Acidity (pKa): 2.36 (carboxyl), 9.60 (amino)
 Structure and properties: Refractive index (n), Dielectric constant (εr), etc

13. CYSTEINE
 Cysteine is a semiessential proteinogenic amino acid with the formula HOOC-CH--
CH₂-SH. The thiol side chain in cysteine often participates in enzymatic reactions,
as a nucleophile.
 Formula: C3H7NO2S
 Molar mass: 121.16 g/mol
 Melting point: 240 °C
 Structure and properties: Refractive index (n), Dielectric constant (εr), etc
 Chiral rotation (D): +9.4° (H2O, c = 1.3)
 Soluble in: Water, Acetic acid

14. GLUTAMIC ACID
 Glutamic acid is an α-amino acid that is used by almost all living beings in the
biosynthesis of proteins. It is non-essential in humans, meaning the body can
synthesize it. It is also an excitatory neurotransmitter, in fact the most abundant
one, in the vertebrate nervous system.
 Formula: C5H9NO4
 Molar mass: 147.13 g/mol
 IUPAC ID: 2-Aminopentanedioic acid
 Melting point: 199 °C
 Boiling point: 333.8 °C
 Soluble in: Water

15. ASPARTIC ACID
 Aspartic acid, is an α-amino acid that is used in the biosynthesis of proteins. Like
all other amino acids, it contains an amino group and a carboxylic acid.
 Formula: C4H7NO4
 Molar mass: 133.11 g/mol
 IUPAC ID: 2-Aminobutanedioic acid
 Solubility in water: 4.5 kg/m³
 Structure and properties: Refractive index (n), Dielectric constant (εr), etc
 Conjugate base: Aspartate

16. ARGININE
 Formula: C6H14N4O2
 Molar mass: 174.2 g/mol
 IUPAC ID: (S)-2-Amino-5-guanidinopentanoic acid
 ChemSpider ID: 227

17. THERONINE
 Threonine is an amino acid that is used in the biosynthesis of proteins. It contains an α-
amino group, a carboxyl group, and a side chain containing a hydroxyl group, making
it a polar, uncharged amino acid. It is essential in humans, meaning the body cannot
synthesize it: it must be obtained from the diet.
 Formula: C4H9NO3
 Molar mass: 119.1192 g/mol
 Acidity (pKa): 2.63 (carboxyl), 10.43 (amino)
 Structure and properties: Refractive index (n), Dielectric constant (εr), etc
 3D model (JSmol): Interactive image; Zwitterion: Interactive image
 Classification: Amino Acid, Proteinogenic amino acid

18. ISOLEUCINE
 Isoleucine is an α-amino acid that is used in the biosynthesis of proteins. It
contains an α-amino group, an α-carboxylic acid group, and a hydrocarbon side
chain with a branch. It is classified as a non-polar, uncharged, branched-chain,
aliphatic amino acid.
 Formula: C6H13NO2
 Molar mass: 131.17 g/mol
 Structure and properties: Refractive index (n), Dielectric constant (εr), etc
 3D model (JSmol): Interactive image; Zwitterion: Interactive image
 Classification: Amino Acid

19. GLYCINE
 Glycine is an amino acid that has a single hydrogen atom as its side chain. It is the
simplest amino acid, with the chemical formula NH₂‐CH₂‐COOH. Glycine is one of
the proteinogenic amino acids. It is encoded by all the codons starting with GG.
 Formula: C₂H₅NO₂
 Molar mass: 75.07 g/mol
 Melting point: 233 °C
 Density: 1.61 g/cm³
 Acidity (pKa): 2.34 (carboxyl), 9.6 (amino)
 Structure and properties: Refractive index (n), Dielectric constant (εr), etc

20. PROLINE
 Proline is an organic acid classed as a proteinogenic amino acid, although it does not
contain the amino group -NH ₂ but is rather a secondary amine. The secondary amine
nitrogen is in the protonated NH₂⁺ form under biological conditions, while the carboxy
group is in the deprotonated −COO⁻ form.
 Molar mass: 115.13 g/mol
 Formula: C5H9NO2
 Melting point: 205 °C
 IUPAC ID: Proline
 Acidity (pKa): 1.99 (carboxyl), 10.96 (amino)
 Structure and properties: Refractive index (n), Dielectric constant (εr), etc

21. VALINE
 Valine is an α-amino acid that is used in the biosynthesis of proteins. It contains an α-
amino group, an α-carboxylic acid group, and a side chain isopropyl group, making it a
non-polar aliphatic amino acid. It is essential in humans, meaning the body cannot
synthesize it: it must be obtained from the diet.
 Formula: C5H11NO2
 Molar mass: 117.151 g/mol
 IUPAC ID: Valine
 Acidity (pKa): 2.32 (carboxyl), 9.62 (amino)
 Structure and properties: Refractive index (n), Dielectric constant (εr), etc
 Soluble in: Water

22. ALANINE
 Alanine is an α-amino acid that is used in the biosynthesis of proteins. It contains
an amine group and a carboxylic acid group, both attached to the central carbon
atom which also carries a methyl group side chain.
 Formula: C3H7NO2
 Molar mass: 89.09 g/mol
 Density: 1.42 g/cm³
 Structure and properties: Refractive index (n), Dielectric constant (εr), etc
 Acidity (pKa): : 2.34 (carboxyl; H2O); 9.87 (amino; H2O);
 Classification: Amino Acid

23. TYROSINE
 L-Tyrosine or tyrosine or 4-hydroxyphenylalanine is one of the 20 standard amino
acids that are used by cells to synthesize proteins. It is a non-essential amino acid
with a polar side group.
 Formula: C9H11NO3
 Molar mass: 181.19 g/mol
 IUPAC ID: Tyrosine
 ChemSpider ID: 5833
 Classification: Amino Acid, Proteinogenic amino acid

24. GLUTAMINE
 Glutamine is an α-amino acid that is used in the biosynthesis of proteins. Its side
chain is similar to that of glutamic acid, except the carboxylic acid group is
replaced by an amide. It is classified as a charge-neutral, polar amino acid.
 Formula: C5H10N2O3
 Molar mass: 146.14 g/mol
 Acidity (pKa): 2.2 (carboxyl), 9.1 (amino)
 Structure and properties: Refractive index (n), Dielectric constant (εr), etc
 Chiral rotation (D): +6.5º (H2O, c = 2)
 Soluble in: Water

25. SERINE
 Serine is an ɑ-amino acid that is used in the biosynthesis of proteins. It contains an
α-amino group, a carboxyl group, and a side chain consisting of a hydroxymethyl
group, classifying it as a polar amino acid.
 Formula: C3H7NO3
 Molar mass: 105.09 g/mol
 Acidity (pKa): 2.21 (carboxyl), 9.15 (amino)
 Structure and properties: Refractive index (n), Dielectric constant (εr), etc
 Classification: Pacifastin

26. PROLINE
 Proline is an organic acid classed as a proteinogenic amino acid, although it does not
contain the amino group -NH ₂ but is rather a secondary amine. The secondary amine
nitrogen is in the protonated NH₂⁺ form under biological conditions, while the carboxy
group is in the deprotonated −COO⁻ form.
 Molar mass: 115.13 g/mol
 Formula: C5H9NO2
 Melting point: 205 °C
 IUPAC ID: Proline
 Acidity (pKa): 1.99 (carboxyl), 10.96 (amino)
 Structure and properties: Refractive index (n), Dielectric constant (εr), etc

27. TYROSINE
 L-Tyrosine or tyrosine or 4-hydroxyphenylalanine is one of the 20 standard amino
acids that are used by cells to synthesize proteins. It is a non-essential amino acid
with a polar side group.
 Formula: C9H11NO3
 Molar mass: 181.19 g/mol
 IUPAC ID: Tyrosine
 ChemSpider ID: 5833
 Classification: Amino Acid, Proteinogenic amino acid

28. ASPARTIC
 Aspartic acid, is an α-amino acid that is used in the biosynthesis of proteins. Like
all other amino acids, it contains an amino group and a carboxylic acid.
 Formula: C4H7NO4
 Molar mass: 133.11 g/mol
 IUPAC ID: 2-Aminobutanedioic acid
 Solubility in water: 4.5 kg/m³
 Structure and properties: Refractive index (n), Dielectric constant (εr), etc
 Conjugate base: Aspartate

29. GLUTAMINE
 Glutamine is an α-amino acid that is used in the biosynthesis of proteins. Its side
chain is similar to that of glutamic acid, except the carboxylic acid group is
replaced by an amide. It is classified as a charge-neutral, polar amino acid.
 Formula: C5H10N2O3
 Molar mass: 146.14 g/mol
 Acidity (pKa): 2.2 (carboxyl), 9.1 (amino)
 Structure and properties: Refractive index (n), Dielectric constant (εr), etc
 Chiral rotation (D): +6.5º (H2O, c = 2)
 Soluble in: Water

30. ASPARAGINE
 Asparagine, is an α-amino acid that is used in the biosynthesis of proteins. It
contains an α-amino group, an α-carboxylic acid group, and a side chain
carboxamide, classifying it as a polar, aliphatic amino acid. It is non-essential in
humans, meaning the body can synthesize it.
 Formula: C4H8N2O3
 Molar mass: 132.12 g/mol
 ChemSpider ID: 6031

31. Branched Chain Amino Acid
 A branched-chain amino acid is an amino acid having an aliphatic side-chain with
a branch. Among the proteinogenic amino acids, there are three BCAAs: leucine,
isoleucine, and valine. Non-proteinogenic BCAAs include 2-aminoisobutyric acid.
 Classification: Amino Acid

32. Amino Acid Neurotransmitter
 An amino acid neurotransmitter is an amino acid which is able to transmit a nerve
message across a synapse. Neurotransmitters are packaged into vesicles that
cluster beneath the axon terminal membrane on the presynaptic side of a synapse
in a process called endocytosis. Wikipedia
 Classification: Amino Acid

33. SARCOSINE
 Sarcosine, also known as N-methylglycine, is an intermediate and byproduct in
glycine synthesis and degradation. Sarcosine is metabolized to glycine by the
enzyme sarcosine dehydrogenase, while glycine-N-methyl transferase generates
sarcosine from glycine.
 Molar mass: 89.093 g/mol
 Formula: C3H7NO2
 Acidity (pKa): 2.36
 Basicity (pKb): 11.64
 UV-vis (λmax): 260 nm
 Heat capacity (C): 128.9 J K−1 mol−1

34. MELANIN
 Melanin is a broad term for a group of natural pigments found in most organisms.
Melanin is produced through a multistage chemical process known as
melanogenesis, where the oxidation of the amino acid tyrosine is followed by
polymerization.
 Chemical formula: C18H10N2O4
 Melting point: < −20 °C (−4 °F; 253 K)
 Molar mass: 318.288 g·mol−1
 Density: 1.6 to 1.8 g/cm3
 PubChem CID: 6325610
 Boiling point: 450 to 550 °C (842 to 1,022 °F; 723 to 823 K)

35. Amino acids are organic compounds that contain amine (–NH2) and carboxyl (–COOH) functional
groups, along with a side chain (R group) specific to each amino acid.[1][2] The key elements of an
amino acid are carbon (C), hydrogen (H), oxygen (O), and nitrogen (N), although other elements are
found in the side chains of certain amino acids. About 500 naturally occurring amino acids are known
(though only 20 appear in the genetic code) and can be classified in many ways.[3] They can be
classified according to the core structural functional groups' locations as alpha- (α-), beta- (β-), gamma-
(γ-) or delta- (δ-) amino acids; other categories relate to polarity, pH level, and side chain group type
(aliphatic, acyclic, aromatic, containing hydroxyl or sulfur, etc.). In the form of proteins, amino acid
residues form the second-largest component (water is the largest) of human muscles and other
tissues.[4] Beyond their role as residues in proteins, amino acids participate in a number of processes
such as neurotransmitter transport and biosynthesis.

36. The structure of an alpha amino acid in its un-ionized form

37. Twenty of the proteinogenic amino acids are encoded directly by triplet codons in the genetic code
and are known as "standard" amino acids. The other two ("nonstandard" or "non-canonical") are
selenocysteine (present in many prokaryotes as well as most eukaryotes, but not coded directly by
DNA), and pyrrolysine (found only in some archaea and one bacterium). Pyrrolysine and
selenocysteine are encoded via variant codons; for example, selenocysteine is encoded by stop
codon and SECIS elementN-formylmethionine (which is often the initial amino acid of proteins in
bacteria, mitochondria, and chloroplasts) is generally considered as a form of methionine rather
than as a separate proteinogenic amino acid. Codon–tRNA combinations not found in nature can
also be used to "expand" the genetic code and form novel proteins known as alloproteins
incorporating non-proteinogenic amino acids.

38. Many important proteinogenic and non-proteinogenic amino acids have biological functions. For
example, in the human brain, glutamate (standard glutamic acid) and gamma-aminobutyric acid
("GABA", nonstandard gamma-amino acid) are, respectively, the main excitatory and inhibitory
neurotransmitters.[17] Hydroxyproline, a major component of the connective tissue collagen, is
synthesised from proline. Glycine is a biosynthetic precursor to porphyrins used in red blood cells.
Carnitine is used in lipid transport. Nine proteinogenic amino acids are called "essential" for humans
because they cannot be produced from other compounds by the human body and so must be taken in
as food. Others may be conditionally essential for certain ages or medical conditions. Essential amino
acids may also differ between species.[b] Because of their biological significance, amino acids are
important in nutrition and are commonly used in nutritional supplements, fertilizers, feed, and food
technology. Industrial uses include the production of drugs, biodegradable plastics, and chiral
catalysts.

39. A polypeptide is an unbranched chain of amino acids :

40. THANK YOU