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1. Muhammad Tjammal Rehman
Tjammalrehman.BIO@tuf.edu.pk
The University of Faisalabad (TUF)
Biochemistry-II
Acknowledgement: The material given here is modified/altered/given as such/copied from books, research papers,
multimedia slides, internet and other online resources. This is only for the guidance of students.
BIOC-202 3(2-1)
DPT-5th

2. TISSUE BIOCHEMISTRY:
Extracellular Matrix

3. TISSUE BIOCHEMISTRY
Tissue biochemistry is the study of the
• Chemical processes,
• Biochemical components (like proteins, lipids, carbohydrates, and nucleic acids),
• and interactions
that occur within and among the cells and extracellular matrices of tissues.
Tissue: “Group of specialized cells is called tissue”
Tissue is a cellular organizational level intermediate between cells and a complete organism.
Types of tissues
Animal tissues can be grouped into four basic types:
• Connective tissue
• Muscular tissue
• Nervous tissue
• Epethelial tissue

4. Extracellular Matrix (ECM)
Most mammalian cells are located in tissues, surrounded by a complex ECM referred to as “connective
tissue” which protects the organs and also provides elasticity where required (eg, in blood vessels,
lungs, and skin).
The term "extracellular” literally means “outside the cell," which explains where the matrix is located.
The extracellular matrix (ECM) is a system of fibers, carbohydrates, and proteins that provides
• Structural
• Biochemical support to cells

5. The ECM contains three major classes of biomolecules
Structural proteins
• Collagen (The most abundant (30%) ECM protein, providing exceptional tensile strength to tissues like
skin, bone, and tendons)
• Elastin (Confers elasticity and recoil properties, such as lungs and large arteries)
• Fibrilin (tissue elasticity)
Specialized Glycoproteins proteins
• Fibronectin
• Laminin
Proteoglycans (Glycosaminoglycans- GAGs)
Extracellular Matrix (ECM)

6. Mechanical Support: Provides the framework that holds tissues together, defining their shape and
strength.
Biochemical Signaling: Acts as a reservoir for growth factors and cytokines, modulating cell behavior
and communication.
Dynamic Regulator: Actively involved in cell adhesion, migration, proliferation, and differentiation,
guiding tissue development and repair.
Extracellular Matrix (ECM)

7. Collagen

8. Collagen: Structure and Types
Collagen's defining feature is its triple helix structure, formed by three polypeptide α-chains. A
crucial aspect of its stability is the repeating Gly-X-Y sequence, where X is often Proline and Y is
Hydroxyproline.
Hydroxylation: Proline and lysine residues undergo hydroxylation (a process requiring Vitamin C),
which is vital for stabilizing the triple helix via hydrogen bonds.
Cross-linking: Lysyl oxidase forms covalent cross-links between collagen fibrils, further
strengthening the tissue.