Collagen Synthesis and Modification

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What percentage of the human body's proteins is composed of collagen?

15%

30%

25% (correct)

20%

What is the characteristic of the repetitive amino acid sequence in collagen?

Gly-X-Y every third residue (correct)

Gly-X-X every third residue

Gly-X-Y every fifth residue

Gly-X-Y every seventh residue

What is the function of hydroxyproline in collagen?

Contributes to H-bonding between α-chains (correct)

Provides flexibility to the collagen molecule

Allows for sharp twisting and confers rigidity

Contributes to the formation of disulfide bonds

What is the characteristic of the α-chains in collagen?

Left-handed helix with 3.3 residues per turn (A) Signup and view all the answers

What is the molecular weight of the collagen triple helix?

300 kDa (B) Signup and view all the answers

What is the characteristic of the collagen triple helix?

A tightly packed, right-handed superhelix (D) Signup and view all the answers

What is the primary function of elastin in connective tissue?

Enabling extensibility and elastic recoil (C) Signup and view all the answers

Which of the following is NOT a type of glycosaminoglycan (GAG)?

Keratin (A) Signup and view all the answers

What is the primary function of fibronectin in the extracellular matrix (ECM)?

Enabling cell adhesion and migration (C) Signup and view all the answers

Which of the following proteoglycans is NOT typically found in the ECM?

Serglycin (A) Signup and view all the answers

What is the primary function of matrix metalloproteinases (MMPs) in the ECM?

Regulating ECM degradation (A) Signup and view all the answers

Which of the following diseases is associated with defects in collagen biosynthesis?

Osteogenesis imperfecta (D) Signup and view all the answers

What is the primary function of hyaluronic acid in the ECM?

Attracting water by osmotic pressure (D) Signup and view all the answers

Which of the following is a characteristic of glycosaminoglycans (GAGs)?

They are unbranched polysaccharides (A) Signup and view all the answers

What is the primary function of integrins in the ECM?

Enabling cell adhesion and signaling (C) Signup and view all the answers

Which of the following is a consequence of defects in GAG degradation?

Mucopolysaccharidoses (A) Signup and view all the answers

What is a consequence of MMPs destroying the ECM?

Release of bound growth factors (C) Signup and view all the answers

What is the purpose of coordinated expression of MMPs and TIMPs?

To facilitate appropriate growth and cell movement (C) Signup and view all the answers

How do MMPs contribute to cancer cell metastasis?

By facilitating ECM remodeling and allowing cells to spread (A) Signup and view all the answers

What is the role of TIMPs in regulating MMP activity?

To inhibit MMP activity (A) Signup and view all the answers

What is a consequence of dysregulation of MMP activity and TIMP expression?

Development of certain clinical disorders, such as cancer and atherosclerosis (C) Signup and view all the answers

What is the primary function of proteoglycans in the extracellular matrix?

To form a scaffold for cell attachment and signaling (D) Signup and view all the answers

What is the characteristic of the ECM in terms of its composition?

It varies in tissues depending on their functions (A) Signup and view all the answers

What is the function of the ECM in terms of the movement of cells and molecules?

To prevent the movement of cells and molecules (B) Signup and view all the answers

What is the characteristic of the adhesion proteins fibronectin and laminin?

They are non-fibrous proteins (D) Signup and view all the answers

What is the primary function of the ECM in terms of organ protection?

To protect organs from mechanical damage (B) Signup and view all the answers

What is the primary mechanism by which MMPs are regulated?

All of the above (D) Signup and view all the answers

What is the characteristic of the ECM in terms of its structure?

It is a porous structure (D) Signup and view all the answers

What is the consequence of dysregulation of MMP activity and TIMP expression?

Facilitation of certain clinical disorders (B) Signup and view all the answers

What is the role of MMPs in cell movement within the ECM?

To facilitate cell movement by remodeling the ECM (A) Signup and view all the answers

What is the consequence of ECM destruction by MMPs?

Release of bound growth factors (B) Signup and view all the answers

What is the requirement for appropriate growth and cell movement?

Coordinated expression of MMPs and TIMPs (C) Signup and view all the answers

What is the primary function of glycosaminoglycans in the extracellular matrix?

To attract and bind water, contributing to tissue turgor (C) Signup and view all the answers

What is the characteristic of hyaluronic acid in the ECM?

It is a large, unbranched polysaccharide (D) Signup and view all the answers

Which of the following GAGs is typically found in cartilage and bone?

Chondroitin sulfate (D) Signup and view all the answers

What is the consequence of defects in GAG degradation?

Mucopolysaccharidoses (B) Signup and view all the answers

What is the primary function of proteoglycans in the ECM?

To determine ECM structure and function (B) Signup and view all the answers

Which of the following is a characteristic of proteoglycans?

They are found in all tissues (D) Signup and view all the answers

What is the role of proteoglycans in cell signaling and behavior?

They regulate cell signaling and behavior (D) Signup and view all the answers

What is the consequence of defects in proteoglycan synthesis?