Biology: Cellular Structures and Junctions

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Questions and Answers

What is the function of desmoglein and desmocollin in desmosomes?

To anchor proteins to the cell membrane

To provide attachment sites for intermediate filaments

To link adjacent cells together (correct)

To regulate cell signaling pathways

Which proteins bind to desmoglein and desmocollin to link them to intermediate filaments?

Plakoglobins and desmoplakins (correct)

Plakophilins and plakoglobins

Desmoplakins and intermediate filaments

Plakophilins and desmoplakins

What is the effect of autoimmune disease pemphigus on desmosomes?

It has no effect on desmosomes

It disrupts the desmosomes that hold skin epithelial cells together (correct)

It strengthens the desmosomes

It increases the expression of desmoglein and desmocollin

What is the primary function of desmosomes?

To provide mechanical strength to tissues Signup and view all the answers

Which of the following tissues is desmosomes most abundant in?

Epithelial tissue Signup and view all the answers

What is the role of plaque proteins in desmosomes?

They provide attachment sites for intermediate filaments Signup and view all the answers

What is the function of desmoplakin in desmosomes?

It provides attachment sites for intermediate filaments Signup and view all the answers

What type of proteins are desmoglein and desmocollin?

Cadherin proteins Signup and view all the answers

What is the role of Cx43, Cx46, and Cx50/α8 in the development of certain diseases?

All of the above Signup and view all the answers

What type of junction allows for the free interchange of substances between cells?

Gap junctions Signup and view all the answers

What is the result of a defect in Desmoglein 3?

Severe blistering of the skin Signup and view all the answers

What is the role of hemidesmosomes in the cell?

They are involved in cell-matrix adhesion Signup and view all the answers

What type of intermediate filaments are found in epithelial cells?

Keratin filaments Signup and view all the answers

What protein binds to laminin in the basal lamina and to keratin intermediate filaments in hemidesmosomes?

Integrin Signup and view all the answers

What type of anchoring junction involves actin filament attachment sites?

Adherens junctions Signup and view all the answers

What is the result of autoantibodies attacking type XVII collagen in the basal lamina?

Blistering skin disease Signup and view all the answers

What type of anchoring junction is involved in the attachment of actin filaments to the extracellular matrix?

Focal adhesions Signup and view all the answers

What is the function of hemidesmosomes in cells?

Cell-matrix adhesion Signup and view all the answers

What is the difference between hemidesmosomes and desmosomes?

Hemidesmosomes have a single dense plaque Signup and view all the answers

What is the name of the protein that is mutated in skin blistering diseases?

Plectin Signup and view all the answers

What type of anchoring junction is involved in the attachment of intermediate filaments to the basal lamina?

Hemidesmosomes Signup and view all the answers

What protein is associated with the basal lamina in hemidesmosomes?

Laminin Signup and view all the answers

What is the consequence of autoantibodies attacking type XVII collagen?

Bullous pemphigoid Signup and view all the answers

What is the result of mutations in plectin?

Late-onset muscular dystrophy with skin blisters Signup and view all the answers

What is the main component of a microvillus?

Actin filaments Signup and view all the answers

What is the function of villin and fimbrin in microvilli?

To cross-link actin filaments into bundles Signup and view all the answers

Where are cilia typically found?

On the surface of epithelial cells of the uterine tubes and respiratory tract Signup and view all the answers

What is the function of cilia?

To move the fluid over the surface of the cell Signup and view all the answers

What is the structure of cilia composed of?

Microtubules Signup and view all the answers

What is the thickness of the glycocalix around microvilli?

Thicker Signup and view all the answers

What is the composition of a triplet microtubule in a basal body?

One complete microtubule fused to two incomplete microtubules Signup and view all the answers

What is the function of basal bodies in cilia and flagella?

To organize the axoneme microtubules Signup and view all the answers

What is the difference between a basal body and a centriole?

Basal bodies have accessory structures such as basal foot and rootlet Signup and view all the answers

What is the result of a defect in the formation of basal bodies in cilia during development?

Internal organs cannot be located at their normal positions Signup and view all the answers

What is the structure that extends from the basal body into the apical cytoplasm?

Rootlet Signup and view all the answers

How many sets of triplet microtubules are found in a basal body?

Nine Signup and view all the answers

What is the movement pattern of cilia at the node during development?

Helical Signup and view all the answers

What is the term for the fibrous material that extends laterally from the basal body?

Basal foot Signup and view all the answers

What is the structure of microtubules?

Hollow tube-like structures composed of 13 protofilaments Signup and view all the answers

What is the function of the basal body in a ciliated cell?

To organize the microtubules of cilia Signup and view all the answers

What is the characteristic feature of stereocilia?

They are long and irregular microvilli Signup and view all the answers

What is the difference between cilia and flagella?

Cilia have a different type of movement than flagella Signup and view all the answers

What is the function of centrioles?

To organize the microtubules of cilia and flagella Signup and view all the answers

What is the structure of flagellum of mammalian spermium?

9+2 microtubule arrangement with 9 additional dense fibers Signup and view all the answers

What is the difference between the movement of flagella and cilia?

Flagella move with an undulating wave-like motion, while cilia move with a beating motion Signup and view all the answers

What is the function of the node in embryonic development?

To produce signal proteins that establish left-right asymmetry Signup and view all the answers

What is the primary function of anchoring junctions?

To provide mechanical support and adhesion between cells or between cells and the extracellular matrix Signup and view all the answers

What is the type of anchoring junction that involves actin filament attachment sites?

Focal adhesions Signup and view all the answers

What is the result of a defect in the protein plectin?

Skin blisters Signup and view all the answers

What is the type of protein that binds to laminin in the basal lamina and to keratin intermediate filaments in hemidesmosomes?

Integrin Signup and view all the answers

What is the type of anchoring junction that involves intermediate filament attachment sites?

Hemidesmosomes Signup and view all the answers

What is the function of the protein integrin in focal adhesions?

To bind to laminin in the basal lamina Signup and view all the answers

What is the consequence of autoantibodies attacking type XVII collagen in the basal lamina?

Blistering skin disease Signup and view all the answers

What is the type of cytoskeletal element involved in focal adhesions?

Actin filaments Signup and view all the answers

What is the primary function of fibrin in blood clots?

To form an elastic network to which cells and other ECM components bind Signup and view all the answers

What is the enzyme responsible for cleaving fibrinogen to form fibrin?

Thrombin Signup and view all the answers

What is the function of von Willebrand Factor (vWF) in thrombus formation?

To form a bridge between collagen in the vessel wall and blood platelets Signup and view all the answers

What is the precursor molecule of fibrin?

Fibrinogen Signup and view all the answers

Which of the following proteins are found in the cytoplasmic plaque of desmosomes?

Plakoglobins, desmoplakins, and plakophilins Signup and view all the answers

What is the enzyme responsible for cleaving plasminogen to form plasmin?

Tissue plasminogen activator Signup and view all the answers

What is the role of plaque proteins in desmosomes?

To link cadherins to intermediate filaments Signup and view all the answers

Which of the following proteins is NOT a component of the cytoplasmic plaque of desmosomes?

Laminin Signup and view all the answers

What is the function of plasmin in the dispersal of blood clots?

To cleave fibrin and promote the dispersal of blood clots Signup and view all the answers

What is the function of the cytoplasmic plaque in desmosomes?

To provide attachment sites for intermediate filaments Signup and view all the answers

What is the binding site for fibrin?

All of the above Signup and view all the answers

What is the structure of fibrinogen molecules?

Elongated structures 45 nm in length with two sets of αα, Bß, and γ chains linked by disulfide bonds Signup and view all the answers

Which of the following is a characteristic of desmosomes?

They provide mechanical strength to the tissue Signup and view all the answers

What is the consequence of autoantibodies attacking desmosomal cadherins in pemphigus?

The disruption of desmosomes and the loss of mechanical strength Signup and view all the answers

Which of the following tissues is desmosomes most abundant in?

Epidermis and heart muscle Signup and view all the answers

What is the function of desmosomes in tissues?

To provide mechanical strength to the tissue Signup and view all the answers

What is the main function of desmosomes in cells?

To provide mechanical strength to tissues Signup and view all the answers

What type of proteins are involved in the attachment of cadherins to intermediate filaments?

Desmoplakin and plakoglobin Signup and view all the answers

What is the shape of the structures on the cytoplasmic face of the junction?

Plaque-shaped Signup and view all the answers

Which of the following tissues is desmosomes most abundant in?

Skin (epidermis) and heart muscle Signup and view all the answers

What is the result of autoantibodies attacking desmosomal cadherins?

Disruption of desmosomes leading to skin blistering Signup and view all the answers

What is the function of desmoglein and desmocollin?

To link adjacent cells together Signup and view all the answers

What is the location of desmoplakin, plakoglobin, and plakophilin in desmosomes?

In the plaque-shaped structures on the cytoplasmic face of the junction Signup and view all the answers

What is the importance of desmosome junctions?

They provide mechanical strength to tissues Signup and view all the answers

What is the primary function of adherens junctions?

To provide strong adhesion between adjacent cells and form attachment sites for actin filaments Signup and view all the answers

What is the role of α-catenin and ß-catenin in adherens junctions?

To link the cytoplasmic domain of E-Cadherin to actin filaments Signup and view all the answers

What is the result of the controlled contraction of actin filament bundles in adherens junctions during early development?

The formation of a neural tube Signup and view all the answers

What is the function of desmosomes?

To provide mechanical binding between cells and act as the strongest points of cell adhesion Signup and view all the answers

What type of anchoring junction involves intermediate filament attachment sites?

Desmosomes Signup and view all the answers

What is the structure of desmosomes?

A button-like point of tight adhesion Signup and view all the answers

What is the role of vinculin in adherens junctions?

To anchor actin filaments to cadherins Signup and view all the answers

What is the function of adherens junctions in vertebrate development?

To play an important role in the formation of the neural tube Signup and view all the answers

Which type of anchoring junctions is involved in the attachment of intermediate filaments to the basal lamina?

Hemidesmosomes Signup and view all the answers

What is the result of autoantibodies attacking type XVII collagen in the basal lamina?

Bullous pemphigoid Signup and view all the answers

Which protein binds to laminin in the basal lamina and to keratin intermediate filaments in hemidesmosomes?

Integrin Signup and view all the answers

What is the result of mutations in plectin?

Both skin blisters and muscular dystrophy Signup and view all the answers

What type of intermediate filaments are found in epithelial cells?

Keratin Signup and view all the answers

What is the function of hemidesmosomes in cells?

Cell-matrix adhesion Signup and view all the answers

What is the main difference between hemidesmosomes and desmosomes?

Hemidesmosomes attach to the basal lamina, while desmosomes attach to other cells Signup and view all the answers

What is the result of a defect in Desmoglein 3?

Pemphigus vulgaris Signup and view all the answers

Which type of skin disease is caused by autoantibodies attacking desmoglein 3?

Pemphigus vulgaris Signup and view all the answers

What is the result of mutations in the plectin protein?

Skin blisters associated with late-onset muscular dystrophy Signup and view all the answers

Which type of anchoring junction involves the attachment of intermediate filaments to the basal lamina?

Hemidesmosomes Signup and view all the answers

What is the role of integrins in hemidesmosomes?

Binding to laminin protein in the basal lamina Signup and view all the answers

What is the consequence of autoantibodies attacking type XVII collagen in the basal lamina?

Bullous pemphigoid Signup and view all the answers

What type of intermediate filaments are found in epithelial cells?

Keratin filaments Signup and view all the answers

What is the role of hemidesmosomes in the cell?

Attachment of cells to the basal lamina Signup and view all the answers

What is the result of a defect in desmoglein 3?

Pemphigus vulgaris Signup and view all the answers

What is the result of autoantibodies attacking type XVII collagen in the basal lamina?

Blisters in the skin Signup and view all the answers

What is the consequence of mutations in plectin?

Skin blisters Signup and view all the answers

Which of the following is associated with skin blistering diseases?

Plectin Signup and view all the answers

What is the role of hemidesmosomes in bullous pemphigoid?

Cell-matrix adhesion Signup and view all the answers

What is the result of a defect in the protein plectin?

Skin blisters Signup and view all the answers

What is the role of integrin in hemidesmosomes?

Binding to laminin in the basal lamina Signup and view all the answers

What is the type of anchoring junction involved in the attachment of intermediate filaments to the basal lamina?

Hemidesmosomes Signup and view all the answers

What is the protein that binds to laminin in the basal lamina and to keratin intermediate filaments in hemidesmosomes?

Integrin Signup and view all the answers

What is the result of autoimmune disease pemphigus on skin epithelial cells?

The desmosomes are disrupted, leading to skin epithelial cell separation. Signup and view all the answers

Which protein is targeted by autoantibodies in pemphigus?

Desmoglein Signup and view all the answers

What is the primary function of desmosomes in the skin?

To provide mechanical strength and adhesion between cells. Signup and view all the answers

Which of the following tissues is desmosomes most abundant in?

All of the above Signup and view all the answers

What is the role of plaque proteins in desmosomes?

To provide attachment sites for intermediate filaments. Signup and view all the answers

Which type of cadherin protein is involved in desmosomes?

Desmoglein and desmocollin Signup and view all the answers

What is the result of disruption of desmosomes in the skin?

Separation of skin epithelial cells Signup and view all the answers

What is the importance of desmosome junctions demonstrated by?

Autoimmune disease pemphigus Signup and view all the answers

Study Notes

Anchoring Junctions

Anchoring junctions can be subclassified according to the cytoskeletal element that is involved.
There are two types of anchoring junctions: actin filament attachment sites and intermediate filament attachment sites.

Actin Filament Attachment Sites

Cell-cell junctions: adherens junctions
Cell-matrix junctions: focal adhesions

Intermediate Filament Attachment Sites

Cell-cell junctions: desmosomes
Cell-matrix junctions: hemidesmosomes

Desmosomes

Strongest points of cell adhesion that provide mechanical binding
Most abundant in tissues that are exposed to mechanical stress (epidermis of the skin, heart muscle)
Cell to cell binding depends on cadherin family of proteins called desmoglein and desmocollin
Contain plaque-shaped structures on the cytoplasmic face of the junction which provide attachment sites for intermediate filaments
Plaque proteins are: plakoglobins, desmoplakins, plakophilins
Desmosomes are found in many tissues, especially abundant in skin (epidermis), heart muscle, and the neck of the uterus
Importance of desmosome junctions is demonstrated by some of the skin autoimmune diseases, such as pemphigus

Hemidesmosomes

Resemble desmosomes morphologically
Cell uses hemidesmosomes to attach to the basal lamina
Have only a single dense plaque on the cytoplasmic surface of the hemidesmosome (hemi=half) that anchors loops of intermediate filaments
Integrin (α6β4) and type XVII collagen (also called BPAG2) attach to the basal lamina
In a blistering skin disease called bullous pemphigoid, autoantibodies attack type XVII collagen
Mutations in plectin cause skin blisters associated with late-onset muscular dystrophy

Focal Adhesions

Bind the cells to the extracellular matrix
Cell to matrix adhesion proteins; integrins responsible for the binding to the matrix
Cytoplasmic domain of the integrin binds indirectly to actin filaments
Integrin's extracellular domains bind to components of extracellular matrix, while the cytoplasmic tail of the β subunit binds indirectly to actin

Microvillus Structure

A bundle of parallel actin filaments extend 0.5μ down into the apical cytoplasm and enter into the terminal web
Actin filaments are cross-linked into closely packed bundles by actin-bundling proteins, villin, and fimbrin, forming the core of a microvillus
Actin filaments are attached to the plasma membrane by lateral arms consisting of myosin I and calmodulin
Glycocalix is thicker around the microvilli, forming a striated border, and is PAS+

Cilia and Flagella

Cilia are eyelash or hair-like processes from the cell surface, motile, and longer than microvilli (5-10μ long, 0.2μ in diameter)
Under the electron microscope, they have a complex internal structure composed of microtubules
250 or more cilia are found in each cell, arranged in parallel rows, and function to move fluid over the surface of the cell
Found in epithelial cells of the upper respiratory tract, uterine tubes (oviducts), and efferent ducts (Ductus efferentes)

Basal Body Structure

At the base of a cilium, a central pair of single microtubules terminates
Each of the peripheral doublets is continuous with a triplet microtubule of the basal body
Three microtubules are fused together and form a triplet microtubule
Basal body resembles a centriole but contains some accessory structures such as basal foot and rootlet

Cilia Function

Ciliary movement is important during development
Dynein arms are absent from cilia in patients with Kartagener's Syndrome
Nodal Cilia cannot move during development, and internal organs cannot be located at their normal positions
Helical beating of cilia at the node, and the origins of left-right asymmetry

Flagella Structure and Function

Flagellum propels sperm, is longer than cilia (100-200 μ), and has the same internal structure as cilia (Axoneme 9+2)
Has a different type of movement (undulating wave type of movement) and is less in number (one or two in a single cell)
Mammalian spermium contains 9 additional dense fibers around the axoneme (9+9+2), which serves a protective function

Microtubule Structure

Microtubules are hollow tube-like or pipe-like structures
The wall of the microtubule is composed of 13 protofilaments
Protofilaments are composed of Tubulin subunits (dimer), which consist of Tubulin α and Tubulin β

Gap Junctions

Site of firm adhesion of cells
Allow free interchange of substances
Important role in regulation of intrauterine development and differentiation
Coordinate function among groups of cells

Anchoring Junctions

Two types: Hemidesmosomes and Focal Adhesions

Hemidesmosomes

Have a single dense plaque on the cytoplasmic surface
Anchor loops of intermediate filaments
Integrins bind to laminin protein in the basal lamina
Intracellular domain binds to an anchor protein (plectin) that binds to keratin intermediate filaments
Found in epithelial cells, attach to basal lamina
Mutations in plectin cause skin blisters
Autoantibodies attack type XVII collagen in bullous pemphigoid, a blistering skin disease

Focal Adhesions

Bind cells to the extracellular matrix
Cell-matrix adhesion proteins; integrins responsible for binding to the matrix
Cytoplasmic domain of the integrin binds indirectly to actin filaments
Integrin's extracellular domains bind to components of extracellular matrix
Cytoplasmic tail of the β subunit binds indirectly to actin

Adhesion Proteins

Fibrin: a major ECM component of blood clots
Forms an elastic network to which cells and other ECM components bind
Polymerization of fibrin to form the network occurs when its precursor molecule fibrinogen is cleaved by the enzyme thrombin
Fibrin has binding interactions with various extracellular components, including fibronectin, heparin, growth factors, and cytokines
Fibrinolysis is mediated by plasmin, which cleaves fibrin

Von Willebrand Factor

Plays a key role in the major response of platelets to vascular injury by mediating the initiation and progression of thrombus formation
Enables cell adhesion to develop by forming a bridge between collagen in the vessel wall and blood platelets

Desmosomes

Strongest points of cell adhesion that provide mechanical binding
Most abundant in tissues that are exposed to mechanical stress (epidermis of the skin, heart muscle)
Cell-to-cell binding depends on cadherin family of proteins called desmoglein and desmocollin
Contain plaque-shaped structures on the cytoplasmic face of the junction which provide attachment sites for intermediate filaments
Plaque proteins are plakoglobins, desmoplakins, and plakophilins
Found in many tissues, especially abundant in skin, heart muscle, and the neck of the uterus
Importance of desmosome junctions is demonstrated by some skin autoimmune diseases, such as pemphigus, where affected individuals make antibodies against their own desmosomal cadherins

Desmosomes

Strongest points of cell adhesion that provide mechanical binding
Most abundant in tissues exposed to mechanical stress (epidermis of the skin, heart muscle)
Contain plaque-shaped structures on the cytoplasmic face of the junction, providing attachment sites for intermediate filaments
Plaque proteins include plakoglobins, desmoplakins, and plakophilins
Two types of cadherins (desmoglein and desmocollin) link adjacent cells together
Cytoplasmic plaque (desmoplakin, plakoglobin, and plakophilin) links the cadherins to intermediate filaments

Importance of Desmosomes

Desmosomal cadherins are targeted in autoimmune diseases such as Pemphigus, leading to blistering of the skin
Affected individuals make antibodies against their own desmosomal cadherins, disrupting desmosomes and causing skin epithelial cells to separate

Intermediate Filaments

Types of intermediate filaments include keratin filaments in epithelial cells and desmin filaments in heart and muscle cells
Intermediate filaments can be subclassified according to the cytoskeletal element involved

Anchoring Junctions

Subclassified into two types:
- Intermediate filament attachment sites
  - Cell-cell junctions (desmosomes)
  - Cell-matrix junctions (hemidesmosomes)
- Actin filament attachment sites
  - Cell-cell junctions (adherens junctions)
  - Cell-matrix junctions (focal adhesions)

Hemidesmosomes

Resemble desmosomes morphologically
Cell uses hemidesmosomes to attach to the basal lamina
Contain a single dense plaque on the cytoplasmic surface that anchors loops of intermediate filaments
Schematic model shows an epithelial cell attached to the basal lamina via hemidesmosomes
Autoantibodies attack type XVII collagen in bullous pemphigoid, a blistering skin disease
Mutations in plectin cause skin blisters associated with late-onset muscular dystrophy

Adherens Junctions

Actin filament bundles are attached by intracellular anchor proteins to cadherins
Cadherins are transmembrane proteins that bind to those of adjacent cells, tying actin filament bundles together
Adherens junctions in the form of adhesion belts between epithelial cells in the small intestine
Role in early development: controlled contraction of actin filament bundles causes epithelial cells to narrow and form a tube in vertebrate development

Anchoring Junctions

Anchoring junctions can be subclassified according to the cytoskeletal element involved
Two types of anchoring junctions:
- Actin filament attachment sites
  - Cell-cell junctions (ADHERENS JUNCTIONS)
  - Cell-matrix junctions (FOCAL ADHESIONS)
- Intermediate filament attachment sites
  - Cell-cell junctions (DESMOSOMES)
  - Cell-matrix junctions (HEMIDESMOSOMES)

Desmosomes

Desmosomes are strongest points of cell adhesion that provide mechanical binding
Most abundant in tissues that are exposed to mechanical stress (Epidermis of the skin, heart muscle)
Cell to cell binding depends on cadherin family of proteins called desmoglein and desmocollin
Desmosomes contain plaque-shaped structures on the cytoplasmic face of the junction which provide attachment sites for intermediate filaments
Plaque proteins: plakoglobins, desmoplakins, plakophilins

Hemidesmosomes

Hemidesmosomes resemble desmosomes morphologically
Hemidesmosomes have only a single dense plaque on the cytoplasmic surface of the hemidesmosome (hemi=half) that anchors loops of intermediate filaments
Hemidesmosomes connect epithelial cells to the basal lamina
Integrin (α6β4) and type XVII collagen (also called BPAG2) attach to the basal lamina

Importance of Desmosomes and Hemidesmosomes

In a blistering skin disease called bullous pemphigoid, autoantibodies attack type XVII collagen
Mutations in plectin cause skin blisters associated with late-onset muscular dystrophy
Cataract, heart malformations, and skin blistering are examples of diseases related to desmosome and hemidesmosome dysfunction

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This quiz covers the structure and function of cells, including desmoglein, pemphigus vulgaris, and intermediate filaments, as well as anchoring junctions and their classification.

Biology: Cellular Structures and Junctions

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Questions and Answers

What is the function of desmoglein and desmocollin in desmosomes?

Which proteins bind to desmoglein and desmocollin to link them to intermediate filaments?

What is the effect of autoimmune disease pemphigus on desmosomes?

What is the primary function of desmosomes?

Which of the following tissues is desmosomes most abundant in?

What is the role of plaque proteins in desmosomes?

What is the function of desmoplakin in desmosomes?

What type of proteins are desmoglein and desmocollin?

What is the role of Cx43, Cx46, and Cx50/α8 in the development of certain diseases?

What type of junction allows for the free interchange of substances between cells?

What is the result of a defect in Desmoglein 3?

What is the role of hemidesmosomes in the cell?

What type of intermediate filaments are found in epithelial cells?

What protein binds to laminin in the basal lamina and to keratin intermediate filaments in hemidesmosomes?

What type of anchoring junction involves actin filament attachment sites?

What is the result of autoantibodies attacking type XVII collagen in the basal lamina?

What type of anchoring junction is involved in the attachment of actin filaments to the extracellular matrix?

What is the function of hemidesmosomes in cells?

What is the difference between hemidesmosomes and desmosomes?

What is the name of the protein that is mutated in skin blistering diseases?

What type of anchoring junction is involved in the attachment of intermediate filaments to the basal lamina?

What protein is associated with the basal lamina in hemidesmosomes?

What is the consequence of autoantibodies attacking type XVII collagen?

What is the result of mutations in plectin?

What is the main component of a microvillus?

What is the function of villin and fimbrin in microvilli?

Where are cilia typically found?

What is the function of cilia?

What is the structure of cilia composed of?

What is the thickness of the glycocalix around microvilli?

What is the composition of a triplet microtubule in a basal body?

What is the function of basal bodies in cilia and flagella?

What is the difference between a basal body and a centriole?

What is the result of a defect in the formation of basal bodies in cilia during development?

What is the structure that extends from the basal body into the apical cytoplasm?

How many sets of triplet microtubules are found in a basal body?

What is the movement pattern of cilia at the node during development?

What is the term for the fibrous material that extends laterally from the basal body?

What is the structure of microtubules?

What is the function of the basal body in a ciliated cell?

What is the characteristic feature of stereocilia?

What is the difference between cilia and flagella?

What is the function of centrioles?

What is the structure of flagellum of mammalian spermium?

What is the difference between the movement of flagella and cilia?

What is the function of the node in embryonic development?

What is the primary function of anchoring junctions?

What is the type of anchoring junction that involves actin filament attachment sites?

What is the result of a defect in the protein plectin?

What is the type of protein that binds to laminin in the basal lamina and to keratin intermediate filaments in hemidesmosomes?

What is the type of anchoring junction that involves intermediate filament attachment sites?

What is the function of the protein integrin in focal adhesions?

What is the consequence of autoantibodies attacking type XVII collagen in the basal lamina?

What is the type of cytoskeletal element involved in focal adhesions?

What is the primary function of fibrin in blood clots?

What is the enzyme responsible for cleaving fibrinogen to form fibrin?

What is the function of von Willebrand Factor (vWF) in thrombus formation?

What is the precursor molecule of fibrin?

Which of the following proteins are found in the cytoplasmic plaque of desmosomes?

What is the enzyme responsible for cleaving plasminogen to form plasmin?

What is the role of plaque proteins in desmosomes?

Which of the following proteins is NOT a component of the cytoplasmic plaque of desmosomes?

What is the function of plasmin in the dispersal of blood clots?

What is the function of the cytoplasmic plaque in desmosomes?

What is the binding site for fibrin?

What is the structure of fibrinogen molecules?

Which of the following is a characteristic of desmosomes?

What is the consequence of autoantibodies attacking desmosomal cadherins in pemphigus?

Which of the following tissues is desmosomes most abundant in?

What is the function of desmosomes in tissues?

What is the main function of desmosomes in cells?

What type of proteins are involved in the attachment of cadherins to intermediate filaments?

What is the shape of the structures on the cytoplasmic face of the junction?

Which of the following tissues is desmosomes most abundant in?

What is the result of autoantibodies attacking desmosomal cadherins?

What is the function of desmoglein and desmocollin?