Extracellular Structures, Cell Adhesion & Cell Junctions

Introduction What do we mean when we use the term extracellular structures? What do we mean when we use the term extracellular structures? From where do extracellular structures come? From where do extracellular structures come? Of what do extracellular structures consist? Of what do extracellular structures consist?

Extracellular Matrix – Animal Cells What are the three types of macromolecules found in the ECM of animal cells? What are the three types of macromolecules found in the ECM of animal cells? What leads to the variety of the ECM? What leads to the variety of the ECM?

Extracellular Matrix – Animal Cells Besides providing stability to the physical structure of tissues, why else is the ECM important to cell function? Besides providing stability to the physical structure of tissues, why else is the ECM important to cell function? The ECM is usually associated with connective tissue. What are some examples of connective tissue? The ECM is usually associated with connective tissue. What are some examples of connective tissue?

Extracellular Matrix – Animal Cells What is the most abundant component of the ECM? What is the most abundant component of the ECM? What do we know about the makeup of collagen? What do we know about the makeup of collagen?

Extracellular Matrix – Animal Cells How is the collagen fiber assembled? How is the collagen fiber assembled?

Extracellular Matrix – Animal Cells Different α chains exist (coded by different genes) Different α chains exist (coded by different genes) Form different types of collagen Form different types of collagen

Extracellular Matrix – Animal Cells What do collagens have in common with skeletal muscle? What do collagens have in common with skeletal muscle? How are elastins different from collagens? How are elastins different from collagens? What kinds of tissues contain elastins? What kinds of tissues contain elastins?

Extracellular Matrix – Animal Cells Structurally how do elastins compare with collagen? Structurally how do elastins compare with collagen?

Extracellular Matrix – Animal Cells What are proteoglycans? What are proteoglycans? What are glycosaminoglycans? What are glycosaminoglycans?

Extracellular Matrix – Animal Cells How are proteoglycans related to the structure of cartilage? How are proteoglycans related to the structure of cartilage?

Extracellular Matrix – Animal Cells What distinguishes hyaluronate from the other GAG’s? What distinguishes hyaluronate from the other GAG’s? What connection exists between proteoglycans and signaling molecules? What connection exists between proteoglycans and signaling molecules?

Extracellular Matrix – Animal Cells What other functions do proteoglycans serve? What other functions do proteoglycans serve? Adhesive glycoproteins (i.e. fibronectin & laminins) also bind cells to ECM. Adhesive glycoproteins (i.e. fibronectin & laminins) also bind cells to ECM.

Extracellular Matrix – Animal Cells What do we know about fibronectins? What do we know about fibronectins? What does fibronectin structure look like? What does fibronectin structure look like?

Extracellular Matrix – Animal Cells What are some of the functions of fibronectins? What are some of the functions of fibronectins? Where are laminins found? Where are laminins found? What function does the basal lamina serve? What function does the basal lamina serve?

Extracellular Matrix – Animal Cells What do we know about the structure of laminin? What do we know about the structure of laminin?

Extracellular Matrix – Animal Cells What are integrins? What are integrins?

Extracellular Matrix – Animal Cells What is the glycocalyx? What is the glycocalyx? What is its function? What is its function?

Cell-Cell Recognition and Adhesion What are the different categories of adhesion receptors? What are the different categories of adhesion receptors? What is the difference between homophilic and heterophilic interactions? What is the difference between homophilic and heterophilic interactions?

Cell-Cell Recognition and Adhesion What characteristics do all CAMs share? What characteristics do all CAMs share? In what kinds of adhesion events do the CAMs participate? In what kinds of adhesion events do the CAMs participate?

Cell-Cell Recognition and Adhesion How are cadherins different from CAMs? How are cadherins different from CAMs? What types of cadherins are there? What types of cadherins are there? What part of the CAM & cadherin affects the specificity and strength of the binding? What part of the CAM & cadherin affects the specificity and strength of the binding?

Cadherin Structure

Cell-Cell Recognition and Adhesion What are lectins? What are lectins? What is the connection between red blood cell types and carbohydrate side chains? What is the connection between red blood cell types and carbohydrate side chains? How does the presence of sialic acid groups affect the destruction of old rbcs? How does the presence of sialic acid groups affect the destruction of old rbcs?

Cell Junctions What are cell junctions? What are cell junctions? What are the three most common types of cell junctions? What are the three most common types of cell junctions?

Cell Junctions What do all adhesive junctions have in common? What do all adhesive junctions have in common? Where are adhesive junctions most commonly found? Where are adhesive junctions most commonly found?

Cell Junctions What kinds of proteins do all adhesive junctions contain? What kinds of proteins do all adhesive junctions contain? What are desmosomes? What are desmosomes?

Cell Junctions What are hemidesmosomes? What are hemidesmosomes? How are adherens junctions different from desmosomes? How are adherens junctions different from desmosomes? What is a focal contact? What is a focal contact?

Cell Junctions What distinguishes a tight junction? What distinguishes a tight junction? Where are tight junctions found? Where are tight junctions found?

Cell Junctions What effects do these junctions have on movement of membrane lipids and proteins? What effects do these junctions have on movement of membrane lipids and proteins?

Cell Junctions What is special about gap junctions? What is special about gap junctions?

Plant Cell Surface What do we presently know about the function of the cell wall? What do we presently know about the function of the cell wall?

Plant Cell Surface In what way is the plant cell wall similar to the ECM of animal cells? In what way is the plant cell wall similar to the ECM of animal cells?

Plant Cell Surface How is hemicellulose different from cellulose? How is hemicellulose different from cellulose? What are pectins? What are pectins?

Plant Cell Surface What makes extensins different from pectins? What makes extensins different from pectins? What are lignins? What are lignins?

Plant Cell Surface How is the cell wall made by the plant cell? How is the cell wall made by the plant cell?

Plant Cell Surface What are plasmodesmata? What are plasmodesmata?