proteins their structure ,types of structures ,there roles in our life there major function at minor and major level .there building blocks .

1. Protein structure and
function
Name: Rohama
Roll no : 24
BS(4th)

2. Outline
• What is protein ?
• Amino acids structure
• How amino acids are linked
• How proteins fold and unfold
• Levels of protein structure
• Relationship between protein structure and function
• The functions of proteins

3. Protein
• Important biological molecule
• Protein/polypeptide is a polymer
• Monomers amino acids
• Basic 20 amino acids
A.a A.a A.a A.a A.a
monomer
Polymer(polypeptide)

4. Amino acids
 Amine group
 Carboxyl group
 Functional group
Different variable groups
Gives different properties to
amino acids

5. Different amino acids

6. Amino acids linkage
Condensation
reaction
>or= 3 amino
acids make
protein

7. Biosynthesis
DNA
GENES
mRNA
protein
Transcription
Translation

8. Levels of protein structure
 4 levels of protein structure
 Based on chemical linkages
1. Primary structure
2. Secondary structure
3. Tertiary structure
4. Quaternary structure

9. Primary structure
Refers to the sequence or order of amino acids
Bonding
 covalently linked by peptide bonds
 Each amino acid is “residue”

10. Secondary structure
Localized arrangement of adjacent amino acids formed as polypeptide
chain folds
 Two main types of secondary structure
 α-helix and the β-strand or β-sheets
bonding
hydrogen bonding

12. Tertiary structure
• Tertiary structure refers to the three-dimensional structure of
monomeric and multimeric protein molecules
• Bondings
hydrogen bonding
ionic bonding
Van der walls interactions
disulfide linkage

14. Quaternary structure
• Quaternary structure is the three-dimensional structure
• Consist of the aggregation of two or more individual polypeptide
chains (subunits)
• They operate as a single functional unit.
dimers trimers
multimers

15. Quaternary structure

16. Functions of protein
• Structural support
• Transporting molecules
• Receiving and sending signals
• Movement
• Defense against diseases
• Catalysis of biochemical reactions
• Hormonal proteins

17. Functions

18. Distribution according to functions

19. Difference between protein and polypeptide