This document provides an introduction to proteins, including:
- Proteins are composed of amino acids joined by peptide bonds to form polypeptide chains. They are essential to the structure and function of tissues.
- Key components of proteins include carbon, hydrogen, oxygen, nitrogen and sometimes sulfur. Properties include solubility in water/acids/alkalies and hydrolysis into amino acids.
- Examples of protein-rich foods are listed like eggs, milk, meat, fish, nuts and beans. The document defines proteins and discusses their essential roles in the body.
2. CONTENTS
★ Introduction of protein
★ Definition of protein
★ Essential components of proteins
★ Properties of proteins
NH2
Amino Acids Peptide bond(-CO-NH-)
Fig.1. Simple Structure of protein
C
O
O
H
PROTEIN
3. INTRODUCTION OF
PROTEIN
★ The term protein is derived from the Greek word
Proteios means primary or holding first place.
★ In 1839, Dutch chemist G.J. Mulder was first to
describe about proteins.
★ Berzelius(Swedish chemist) suggested the name
protein.
★ Proteins are high molecular organic compound that
consists of the long polypeptide chain of amino
acids monomer.
★ They are essential for the structure, function and
regulation of the body’s tissues and organs.
4. ★ Proteins are made up of similar units called amino
acids, which are building blocks of proteins. They are
attached to one another by peptide bonds forming a
long chain of proteins.
★ The proteins are important dietary constituents that
play vital role in the body.
★ Proteins are required for the synthesis of protoplasm,
enzymes, hormones etc.
★ Lack of proteins in the day to day diet leads to a
variety of deficiency syndromes like improper body
growth and other disorder.
★ Daily requirements of proteins for adult- 60 to
80g/day.
5. EXAMPLES OF PROTEINS
➔ Followings are rich sources of proteins:-
★ Eggs
★ Milk
★ Beef
★ Mutton
★ Fish
★ Liver
★ Nuts
★ Beans
★ Cereals
6. DEFINITION
★ Proteins may be defined as the “high
molecular weight mixed polymer of
amino acids joined together with peptide
linkage (-CO-NH-)”.
★ It is also defined as “the complex
nitrogenous substances which are found
in the all biological system”.
8. PROPERTIES OF PROTEINS
★ Proteins are soluble in water, acids and alkalies.
★ Proteins are colorless and tasteless.
★ They form colloidal solution.
★ All proteins give color reaction when treated with certain
reagent.
★ Proteins are hydrolyzed into constituent amino acids on
boiling with acids and alkalies.
★ Proteins contains carbon, hydrogen, oxygen, nitrogen
and small amount of sulfur.
★ There is a wide variation in the protein shape, it may be
globular, oval, fibrous or elongated.
