Amino Acids & Protiens:
Amino Acids are molecules, which contain two functional groups, one is carboxylic group and another is amino group.
Acidic Amino Acid:
These amino acids contain a second carboxyl group or a potential carboxyl group in the form of carboxamide.
Basic Amino Acids:
These contain a second basic group which may be an amino group.
Essential & Non-Essential Amino Acids:
Those amino acids which must be supplied to our diet as are not synthesized in body are known as essential amino acids.
Ex: Valine, Phenylalanine, Arganine, Lysine,Histadine.
Those amino acids which are synthesized in body are non-essential amino acids.
Ex:Glycine, Alanine, Tyrosine, Serine, Cystine,
Zwiter Ion:
Amino acids contain both acidic carboxyl group -(COOH) and basic amino group in the same molecules.
In aqueous solution, the acidic carboxyl group can lose a proton and basic amino group can gain a proton in a kind of internal acid – base reaction. The product of this internal reaction is called a Dipolar or a Zwitter ion.
Iso-electric Point:
At a certain pH (i.e. H+ concentration), the amino acid molecules show no tendency to migrate towards any of the electrodes and exists as a neutral dipolar ion, when placed in electric field is known as isoelectric point.
Peptide and Proteins:
Proteins are formed by joining the carboxyl group of one amino to the α - amino group of another acid.
The bond formed between two amino acids by the elimination of water molecules is called peptide linkage.
Define Proteins:
Proteins are large macromolecules consisting chain of amino acids that plays an important role in many body functions.
There are 22 different amino acids found.
Classification of Proteins:
There are two methods for classifying proteins.
1)Classification according to Composition
2)Classification according to Functions
1)Classification according to Composition:
i)Simple Proteins:
Simple proteins are those which yield only α-amino acids upon hydrolysis.
Simple proteins are composed of chain of amino acid unit only joined by peptide linkage.
Examples are: Egg (albumin); Serum (globulins); Wheat (Glutelin); Rice (Coryzenin)
2)Conjugated Proteins:
Conjugated proteins are those which yield α - amino acids plus a non protein material on hydrolysis.
The non protein material is called the prosthetic group.
Example: Casein in milk, Hemoglobin, Chlolesterol
According to molecular shape, proteins are further classified into two types.
(A) Fibrous protein
(a) These are made up of polypeptide chain that are parallel to the axis & are held together by strong hydrogen and disulphide bonds.
(b) They can be stretched & contracted like thread.
(c) They are usually insoluble in water.
Example: Keratin (hair, wool, silk & nails); Myosin (muscle)
(B) Globular Proteins
(a) These have more or less spherical shape (compact structure).
(b) α - amino helix are tightly held bonding; H – bonds, disulphide bridges, ionic or salt bridges:
Examples: Albumin (egg)
Classification according to Functions
The functional classification includes following groups.
a) Structural Proteins
These are the fibrous proteins such as collogen (skin, cartilage & bones) which hold living system together.
b) Blood Proteins
(i) The major proteins constituent of the blood are albumin hemoglobin & fibrinogen.
(ii) Their presence contribute to maintenance of osmotic pressure, oxygen transport system & blood coagulation respectively.
Function of Protein:
1) Storage
2) Transport
3) Structural Material
4) Metabolic Growth Regulator
5) Control of Physiological Functions
6) Catalytic Activity
7) Hormonal
8) Toxicity by Foreign Proteins
Properties of Proteins:
i) Optical Property
ii) Colloidal
iii) Solubility
iv) Amphoteric Nature
Amino Acids are molecules, which contain two functional groups, one is carboxylic group and another is amino group.
Acidic Amino Acid:
These amino acids contain a second carboxyl group or a potential carboxyl group in the form of carboxamide.
Basic Amino Acids:
These contain a second basic group which may be an amino group.
Essential & Non-Essential Amino Acids:
Those amino acids which must be supplied to our diet as are not synthesized in body are known as essential amino acids.
Ex: Valine, Phenylalanine, Arganine, Lysine,Histadine.
Those amino acids which are synthesized in body are non-essential amino acids.
Ex:Glycine, Alanine, Tyrosine, Serine, Cystine,
Zwiter Ion:
Amino acids contain both acidic carboxyl group -(COOH) and basic amino group in the same molecules.
In aqueous solution, the acidic carboxyl group can lose a proton and basic amino group can gain a proton in a kind of internal acid – base reaction. The product of this internal reaction is called a Dipolar or a Zwitter ion.
Iso-electric Point:
At a certain pH (i.e. H+ concentration), the amino acid molecules show no tendency to migrate towards any of the electrodes and exists as a neutral dipolar ion, when placed in electric field is known as isoelectric point.
Peptide and Proteins:
Proteins are formed by joining the carboxyl group of one amino to the α - amino group of another acid.
The bond formed between two amino acids by the elimination of water molecules is called peptide linkage.
Define Proteins:
Proteins are large macromolecules consisting chain of amino acids that plays an important role in many body functions.
There are 22 different amino acids found.
Classification of Proteins:
There are two methods for classifying proteins.
1)Classification according to Composition
2)Classification according to Functions
1)Classification according to Composition:
i)Simple Proteins:
Simple proteins are those which yield only α-amino acids upon hydrolysis.
Simple proteins are composed of chain of amino acid unit only joined by peptide linkage.
Examples are: Egg (albumin); Serum (globulins); Wheat (Glutelin); Rice (Coryzenin)
2)Conjugated Proteins:
Conjugated proteins are those which yield α - amino acids plus a non protein material on hydrolysis.
The non protein material is called the prosthetic group.
Example: Casein in milk, Hemoglobin, Chlolesterol
According to molecular shape, proteins are further classified into two types.
(A) Fibrous protein
(a) These are made up of polypeptide chain that are parallel to the axis & are held together by strong hydrogen and disulphide bonds.
(b) They can be stretched & contracted like thread.
(c) They are usually insoluble in water.
Example: Keratin (hair, wool, silk & nails); Myosin (muscle)
(B) Globular Proteins
(a) These have more or less spherical shape (compact structure).
(b) α - amino helix are tightly held bonding; H – bonds, disulphide bridges, ionic or salt bridges:
Examples: Albumin (egg)
Classification according to Functions
The functional classification includes following groups.
a) Structural Proteins
These are the fibrous proteins such as collogen (skin, cartilage & bones) which hold living system together.
b) Blood Proteins
(i) The major proteins constituent of the blood are albumin hemoglobin & fibrinogen.
(ii) Their presence contribute to maintenance of osmotic pressure, oxygen transport system & blood coagulation respectively.
Function of Protein:
1) Storage
2) Transport
3) Structural Material
4) Metabolic Growth Regulator
5) Control of Physiological Functions
6) Catalytic Activity
7) Hormonal
8) Toxicity by Foreign Proteins
Properties of Proteins:
i) Optical Property
ii) Colloidal
iii) Solubility
iv) Amphoteric Nature
v) Denaturation of Proteins etc
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