Extracellular Matrix Overview
43 Questions
4 Views

Choose a study mode

Play Quiz
Study Flashcards
Spaced Repetition
Chat to Lesson

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What is the primary structural composition of Chondroitin sulfate?

  • D-Glucoronic acid + D-galactose
  • D-Glucoronic acid + Galactosamine (correct)
  • L-iduronic acid + Galactosamine
  • D-Glucuronic acid + Glucosamine

Which GAG does NOT contain uronic acid?

  • Keratan sulfate (correct)
  • Chondroitin sulfate
  • Heparin
  • Dermatan sulfate

Which of the following GAGs is primarily responsible for maintaining corneal transparency?

  • Chondroitin sulfate
  • Dermatan sulfate
  • Hyaluronic acid
  • Keratan sulfate I (correct)

What is a key function of Heparin in the body?

<p>Serving as an anticoagulant (C)</p> Signup and view all the answers

Which GAG aggregates primarily in cartilage and plays a role in its compressibility?

<p>Chondroitin sulfate (D)</p> Signup and view all the answers

Which GAG can be degraded by an enzyme known as hyaluronidase?

<p>Hyaluronic acid (D)</p> Signup and view all the answers

Where is Heparan sulfate predominantly found?

<p>As a ubiquitous component of cell surface (C)</p> Signup and view all the answers

Which of the following is NOT a known function of hyaluronic acid?

<p>Regulation of osmotic pressure in blood vessels (A)</p> Signup and view all the answers

Which GAG has multiple sulfate groups and is known for its role as an anticoagulant?

<p>Heparin (B)</p> Signup and view all the answers

In which type of connective tissue is Keratan sulfate II predominantly found?

<p>Loose connective tissues (D)</p> Signup and view all the answers

What is one of the main functions of glycosaminoglycans in connective tissues?

<p>To act as a natural lubricant in the joints (C)</p> Signup and view all the answers

Which glycosaminoglycan is specifically known for binding large amounts of water?

<p>Chondroitin sulfates (B)</p> Signup and view all the answers

What outcomes are associated with hereditary enzyme deficiencies related to glycosaminoglycans?

<p>Mucopolysaccharidoses (B)</p> Signup and view all the answers

Which of the following symptoms is NOT typically associated with mucopolysaccharidosis?

<p>Severe muscle hypertrophy (D)</p> Signup and view all the answers

What structural feature do glycosaminoglycans possess that contributes to their function?

<p>Repeating disaccharide units (D)</p> Signup and view all the answers

What is the primary function of the hyaluronidase enzyme present in semen?

<p>To degrade the gel surrounding the ovum (A)</p> Signup and view all the answers

Which of the following characteristics is unique to hyaluronic acid compared to other glycosaminoglycans (GAGS)?

<p>Non-sulfated (B)</p> Signup and view all the answers

What type of genetic inheritance is primarily associated with mucopolysaccharidoses (MPS)?

<p>Autosomal recessive (A)</p> Signup and view all the answers

What enzyme deficiency is responsible for Hurler's syndrome?

<p>Alpha-L-iduronidase (C)</p> Signup and view all the answers

Which of the following features is NOT associated with dysotosis multiplex?

<p>Increased height (B)</p> Signup and view all the answers

What distinguishes Hunter's syndrome from Hurler's syndrome?

<p>It is due to a deficiency of iduronate sulfatase (D)</p> Signup and view all the answers

What is a common consequence of the accumulation of glycosaminoglycans in mucopolysaccharidoses?

<p>Organomegaly (C)</p> Signup and view all the answers

What enzyme deficiency is implicated in the structural abnormalities and mental retardation observed in the 5-year-old boy?

<p>Alpha-L-iduronidase (D)</p> Signup and view all the answers

How does Sanfilipo's syndrome primarily manifest in affected individuals?

<p>Mental retardation with mild structural features (C)</p> Signup and view all the answers

Which of the following is not a known feature of mucopolysaccharidoses?

<p>Hyperactive behavior (D)</p> Signup and view all the answers

Which class of biomolecules primarily provides structural support in the extracellular matrix (ECM)?

<p>Structural proteins (C)</p> Signup and view all the answers

What is a significant consequence of GAGS accumulation in mucopolysaccharidoses?

<p>Skeletal deformities and mental retardation (A)</p> Signup and view all the answers

What type of sugar forms the repeating disaccharide units in glycosaminoglycans (GAGs)?

<p>Amino sugars and uronic acids (B)</p> Signup and view all the answers

What is one major function of glycosaminoglycans in the extracellular matrix?

<p>Water binding and producing a gel-like matrix (C)</p> Signup and view all the answers

Which of the following is NOT a component of the extracellular matrix?

<p>Nucleotides (C)</p> Signup and view all the answers

Which of the following statements correctly describes glycosaminoglycans?

<p>They consist of large complexes of negatively charged carbohydrates. (A)</p> Signup and view all the answers

What type of cells secrete the extracellular matrix components?

<p>Connective tissue cells (A)</p> Signup and view all the answers

Which glycosaminoglycan is primarily associated with forming proteoglycans?

<p>Chondroitin sulfate (C)</p> Signup and view all the answers

What is the enzyme defect responsible for Hurler's Syndrome?

<p>a-L-iduronidase (A)</p> Signup and view all the answers

Which mucopolysaccharidosis is associated with the accumulation of keratan sulfate?

<p>Morquio's Syndrome (A)</p> Signup and view all the answers

What symptom is not typically associated with MPS I (Hurler Syndrome)?

<p>Severe skeletal deformities (A)</p> Signup and view all the answers

Which of the following mucopolysaccharidoses is X-linked?

<p>MPS II (D)</p> Signup and view all the answers

The lack of which enzyme is responsible for Sanfilippo's Syndrome?

<p>One of four degradative enzymes (A)</p> Signup and view all the answers

Which of the following statements regarding Mucopolysaccharidosis III (Sanfilippo Syndrome) is correct?

<p>It primarily results in mental retardation with little structural change. (B)</p> Signup and view all the answers

What type of structural changes are common in MPS I (Hurler Syndrome)?

<p>Unusual facial features and skeletal abnormalities (C)</p> Signup and view all the answers

Which mucopolysaccharidosis results from a defect in N-acetylglucosamine-4-sulfatase?

<p>Maroteaux-Lamy's Syndrome (B)</p> Signup and view all the answers

How does heparan sulfate affect tumor cell behavior?

<p>It reduces adhesiveness of tumor cells on their surface. (A)</p> Signup and view all the answers

What is the primary consequence of GAG accumulation in mucopolysaccharidosis?

<p>Mental retardation and skeletal deformities (B)</p> Signup and view all the answers

Flashcards

Glycosaminoglycans (GAGs)

Large, negatively charged polysaccharide chains found in the extracellular matrix, providing a gel-like structure.

Extracellular Matrix (ECM)

A mesh of proteins and GAGs that provides structural support and biochemical signals to cells.

GAG Structure

Long, unbranched chains of repeating disaccharide units (amino sugar + uronic acid).

GAG function

GAGs bind large amounts of water, creating a gel-like matrix that cushions and supports tissues.

Signup and view all the flashcards

ECM components

The ECM includes fibrous proteins like collagen and elastin, specialized proteins like fibronectin and proteoglycans, and glycosaminoglycans (GAGs).

Signup and view all the flashcards

Proteoglycans

Proteins bonded to glycosaminoglycans (GAGs).

Signup and view all the flashcards

Disaccharide units

The repeating sugar units forming the GAG chain.

Signup and view all the flashcards

Uronic acid

A type of sugar found in GAGs.

Signup and view all the flashcards

Chondroitin Sulfate

Most abundant GAG in the body, found in cartilage, tendons, ligaments, and aorta. It forms proteoglycan aggregates, contributing to cartilage's compressibility.

Signup and view all the flashcards

Keratan Sulfate (KS)

Heterogeneous GAG without uronic acid; KS I is in the cornea, maintaining transparency, while KS II is in loose connective tissues.

Signup and view all the flashcards

Heparin

Intracellular GAG in mast cells, lining arteries in liver, lungs, and skin. Acts as an anticoagulant.

Signup and view all the flashcards

Dermatan Sulfate

GAG found in skin, cardiac valves, and blood vessels, maintaining eye shape (sclera).

Signup and view all the flashcards

Heparan Sulfate

Extracellular GAG, similar to heparin but with some acetylated glycosamines; a component of the basement membrane.

Signup and view all the flashcards

Hyaluronic Acid

Sulfate-free GAG; a viscous, clear substance found in joints, eyes, and connective tissues. Acts as a lubricant and shock absorber.

Signup and view all the flashcards

GAG (Glycosaminoglycans)

Long, unbranched polysaccharide chains made of repeating disaccharide units.

Signup and view all the flashcards

Hyaluronidase

Enzyme that degrades hyaluronic acid by breaking β(1→4) linkages.

Signup and view all the flashcards

Collagen

A fibrous structural protein present in connective tissues, bound to chondroitin sulfate for supportive structure.

Signup and view all the flashcards

GAGs

Large molecules made up of repeating sugar units that are negatively charged and found in the extracellular matrix.

Signup and view all the flashcards

GAG Types

Different types of GAGs have different properties: Hyaluronic acid, chondroitin sulfate, keratan sulfate, dermatan sulfate, and heparan sulfate.

Signup and view all the flashcards

GAGs and Hereditary Disorders

Defects in the breakdown of GAGs can lead to certain genetic disorders like mucopolysaccharidoses.

Signup and view all the flashcards

Mucopolysaccharidoses (MPS)

A group of genetic disorders caused by a deficiency in enzymes that break down GAGs, leading to an accumulation of GAGs in cells and tissues.

Signup and view all the flashcards

Hyaluronidase's role in fertilization

The enzyme hyaluronidase in semen breaks down the hyaluronic acid surrounding the ovum, enabling sperm to penetrate.

Signup and view all the flashcards

Hyaluronic acid vs. other GAGS

Hyaluronic acid is unique because it's non-sulfated & has a different structure of disaccharide units compared to other glycosaminoglycans (GAGs)

Signup and view all the flashcards

MPS cause

Deficiency in lysosomal hydrolases needed to break down GAGs, leading to their accumulation.

Signup and view all the flashcards

MPS symptoms

Accumulated GAGs cause skeletal deformities, mental retardation, and other issues.

Signup and view all the flashcards

Hurler's syndrome (MPS I)

Type of MPS; deficiency in alpha-L-iduronidase, causing heparan sulfate & dermatan sulfate buildup.

Signup and view all the flashcards

Hunter's syndrome (MPS II)

MPS type caused by iduronate sulfatase deficiency; X-linked inheritance.

Signup and view all the flashcards

Sanfilipo syndrome (MPS III)

MPS type with deficiency in enzymes that break down heparan sulfate, significant mental retardation.

Signup and view all the flashcards

Dysostosis Multiplex

A disorder characterized by severe abnormalities in cartilage and bone development, along with other symptoms

Signup and view all the flashcards

Inheritance Pattern (MPS)

Mostly autosomal recessive, except Hurler's (X-linked).

Signup and view all the flashcards

Hurler Syndrome

A lysosomal storage disease caused by a deficiency in L-iduronidase, leading to the buildup of dermatan sulfate and heparan sulfate, resulting in mental retardation and structural changes.

Signup and view all the flashcards

Hunter Syndrome

An X-linked lysosomal storage disease caused by a deficiency in iduronate sulfatase, resulting in the accumulation of heparan sulfate and dermatan sulfate in various tissues.

Signup and view all the flashcards

Sanfilippo Syndrome

A lysosomal storage disease caused by a deficiency in one of four enzymes involved in breaking down heparan sulfate, resulting in severe mental retardation but minimal structural changes.

Signup and view all the flashcards

Morquio Syndrome

A lysosomal storage disease caused by a deficiency in either galactose-6-sulfatase or beta-galactosidase, leading to the accumulation of keratan sulfate, resulting in skeletal deformities but normal intelligence.

Signup and view all the flashcards

What is the role of Hyaluronic Acid in Cancer?

Hyaluronic acid is a GAG that is overproduced by tumor cells, aiding in cell migration through the extracellular matrix, facilitating tumor spread.

Signup and view all the flashcards

What is the role of Heparan Sulfate in Cancer?

Heparan sulfate is a GAG that plays a role in cell adhesion. Tumor cells often have less heparan sulfate at their surface, reducing their adhesiveness and promoting spread.

Signup and view all the flashcards

What are GAGs?

GAGs are long chains of sugar carbohydrates within cells that contribute to building bone, cartilage, tendons, corneas, skin, and connective tissue.

Signup and view all the flashcards

How do Chondrodystrophies affect the body?

They are autosomal recessive diseases that affect proper cartilage development and skeletal system maintenance due to defects in the sulfation of growing GAG chains.

Signup and view all the flashcards

Study Notes

Extracellular Matrix (ECM)

  • ECM is a collection of extracellular molecules secreted by cells.
  • It provides structural and biochemical support to surrounding cells.
  • Composition of ECM varies between multicellular structures.
  • Functions include cell adhesion and cell-to-cell communication.

Glycosaminoglycans (GAGs)

  • GAGs are large complexes of negatively charged heteropolysaccharide chains.
  • They have a special ability to bind large amounts of water.
  • GAGs produce a gel-like matrix, forming the basis of the body's ground substance surrounding cells.

Composition of ECM

  • ECM is composed of structural proteins, specialized proteins, and proteoglycans.
  • Structural proteins include collagen and elastin.
  • Specialized proteins include fibrillin, fibronectin, and laminin.
  • Proteoglycans are a compound of protein bonded to a mucopolysaccharide group.

Functions of ECM

  • Binding and packing of tissues (connective tissue proper)
  • Connecting, anchoring, and supporting the body and organs.
  • Transport of metabolites between capillaries and tissues.
  • Essential for processes like growth, wound healing, and fibrosis.
  • Defense against infection.
  • Repair of injury via cell proliferation and fiber formation.
  • Fat storage (linked to age, sex, nutrition, and disease).
  • Role in development, inflammatory states, and cancer cell spread.

Functions of GAGs

  • Major component of the extracellular matrix.
  • Form a gel-like matrix, acting as a cushion.
  • Attract water and increase viscosity.
  • Lubricate joints.
  • Provide flexibility and elasticity to cartilage.

Classification of GAGs

  • GAGs are classified as sulfate-free (e.g., hyaluronic acid) and sulfate-containing (e.g., chondroitin sulfate, keratan sulfate, heparin, and heparan sulfate, dermatan sulfate).

Specific GAG examples

  • Hyaluronic acid: Sulfate-free, important component of synovial fluid, vitreous humor, and connective tissues.
  • Chondroitin sulfate: Found in cartilage.
  • Keratan sulfate: Found in the cornea and loose connective tissues.
  • Heparin: Intracellular, functions as an anticoagulant and lipoprotein lipase activator.
  • Heparan sulfate: A component of basement membranes and cell surfaces.
  • Dermatan sulfate: Found in skin, cardiac valves, and blood vessels.

Mucopolysaccharidoses (MPS)

  • Rare inborn errors in the degradation of glycosaminoglycans
  • Hereditary disorders (usually autosomal recessive, except for MPSII which is X-linked)
  • Lysosomal hydrolases for GAGs are deficient.
  • GAGs accumulate, leading to symptoms such as skeletal and extracellular matrix deformities, and mental retardation.

Examples of MPS diseases

  • Hurler syndrome (MPS I): Deficiency in α-L-iduronidase activity.
  • Hunter syndrome (MPS II): Deficiency in iduronate-2-sulfatase activity.
  • Sanfilippo syndrome (MPS III): Deficiency in one of the four enzymes needed to break down heparan sulfate.
  • Morquio syndrome (MPS IV): Deficiency in galactosamine-6-sulfatase, or N-acetylgalactosamine-6-sulfatase leads to accumulation of keratan sulfate.
  • Scheie syndrome (MPS I): milder form of Hurler syndrome.
  • Maroteaux-Lamy syndrome (MPS VI): Deficiency in N-acetylgalactosamine-6-sulfatase.
  • Sly syndrome (MPS VII): Deficiency in β-glucuronidase.

Dysotosis Multiplex

  • Severe abnormalities in the development of cartilage and bone (chondrodystrophic skeletal changes)
  • Deposition of a lipid-like substance in various tissues.

Association of GAGs with Cancer

  • Increased production of hyaluronic acid frequently observed in tumor cells.
  • Lower heparan sulfate levels associated with a lack of adhesiveness in some tumor cells.

Studying That Suits You

Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

Quiz Team

Related Documents

Lec1 Glucosamineglycans PDF

Description

This quiz offers an overview of the Extracellular Matrix (ECM), its composition, and its key functions in tissue support and cell communication. Additionally, it covers Glycosaminoglycans (GAGs) and their role in forming the matrix. Test your understanding of these crucial biological components.

More Like This

Use Quizgecko on...
Browser
Open
Browser
Browser