This document discusses the structure and properties of proteins. It begins with an introduction stating that proteins are polymers of amino acids and are involved in most body functions. It then discusses the primary, secondary, tertiary, and quaternary levels of protein structure. The primary structure is the amino acid sequence. Secondary structures include alpha helices and beta pleated sheets formed by hydrogen bonds. Tertiary structure is determined by interactions between amino acid side chains. Quaternary structure results from multiple polypeptide subunits aggregating. Proteins have various properties like solubility, molecular weight, and shape. They also have important functions like structure, enzymes, hormones, and more.

1. DEPARTMENT OF MICROBIOLOGY
BARKATULLAH UNIVERSITY
BHOPAL
s
presented by :-
Harishchandra Ahirwar
(M.Sc. I Sem.)

2. STRUCTURE AND PROPERTIES OF
PROTEINS

3. CONTENTS
1. Introduction
2. History
3. Structure
A. Primary
B. Secondary
C. Tertiary
D. Quaternary
4. Properties
5. Function
6. Summary

4. INTRODUCTION
 Protiens are the most abundant organic
molecules of the living system.
 Proteins are the polymer of Amino Acids.
 The term protien is generally used for a
polypeptide containing more than 50 amino
acids.
 They are involved in most of our body’s
function.

5. HISTORY
 The term ‘Protein’ is derived from a Greek
Word ‘Proteios’ meaning ‘holding the first
place.
 Berzelius (swedish chemist) suggested the
name Protein.
 Mulder (dutch chemist) in 1838 used the
term Protein.

6. STRUCTURE OF PROTEIN
1. Primary structure
2. Secondary structure
3. Tertiary structure
4. Quaternary structure

7. Primary Structure of а Protein
 The primary structure of а protein is the sequence of
amino acids present in its peptide chain.
 The end with the free H3N+ group is called the N-
terminal end, and the end with the free СОО- group is
called the С-terminal end...

8. PRIMARY STRUCTURE

9. Secondary structure
The secondary structure of a
protein results from hydrogen
bonds at regular intervals along
the polypeptide backbone.
–Typical shapes that
develop from secondary
structure are coils (an alpha
helix) or folds (beta pleated
sheets).

10. ALPHA HELIX
 The alpha helix structure resembles а coiled helical spring,
with the coil configuration maintained by hydrogen bonds
between N – Н and С= О groups of every fourth amino acid.
Alpha Helix

11.  The beta pleated sheet secondary structure involves amino acid
chains that are almost completely extended.
Beta pleated sheet

12. • Tertiary structure is determined by a variety of interactions
among R groups and the polypeptide backbone.
– These interactions include hydrogen bonds , ionic
bonds hydrophobic and van der waals interactions .
Tertiary structure

13. TERTIARY STRUCTURE

14. • Quaternary structure results from the
aggregation of two or more polypeptide
subunits.
–Collagen is a fibrous protein of three
polypeptides that are supercoiled like a rope.
• This provides the structural strength for their
role in connective tissue.
–Haemoglobin is a globular protein with two
copies of two kinds of polypeptides.
Quaternary structure

16. PROPERTIES OF PROTEINS
1. Solubility:-Protein form colloidal solution instead of true
solutions in water.
2. Molecular weight:-Proteins vary in their molecular
weight, dependent on no. of Amino acid residues.
3. Shape:-Wide variation in the protein shape, may be
globular (insulin), oval (albumin), fibrous (fibrinogen).
4. Isoelectric pH:-At isoelectric pH, proteins exist as
dipolar ions.
5. Acidic & basic proteins
6. Precipitation of proteins

17. FUNCTION OF PROTEINS
Proteins perform a great variety of specialized and
essential function in the living cells
 These functions are grouped as
 Static (Structural)
 Dynamic
 Structural functions :- Certain protiens are primarily
responsible for structure and strength of body.
 These include collagen and elastin found in bone
matrix, vascular system and other organs.
 Dynamic functions :- The dynamic functions of
protiens are as acting like enzymes , hormones, blood
clotting factors ,immunoglobins,

18. REFRENCES
BIOCHEMISTRY BY Dr. U. Satyanarayana
TEXTBOOK OF BIOCHEMISTRY BY Jain & Jain
 Images from google

19. THANK
YOU