Answer to Question #285975 in Cell Biology for Sun

Question

Compare and contrast the structure and function of collagens to the other abundant extracellular matrix components.

Answer 1

The major component: of the extracellular matrix are collagen; proteoglycan; fibronectin and laminin_ Describe the major function of each component How is it possible for integrins to perform outside-in" and "inside out" signaling? What is the function of hemidesmosomes and where would You expect to find them in the cell (apical basal or lateral). Describe the Tole of selectins and integrin during the inflammation response_ Selectins and Cadherins are both glycoproteins that attach cells to cells in - calcium dependent fashion; how are they different? What causes metastatic cells to be less adhesive and able to penetrate several cellular barriers? C Give functions of adherens junctions OR desmosomes_ Where are tight junctions located and what is their function? 10. What is the major function of gap junction and what protein form them? 11. What are tunneling nanotubes? 12. What is the name of the structure in plant cells that is similar to gap junctions animal cell:? 13. Compare and contrast the extracellular matrix of animal cells with the cell wall and matrix of plant cells_ 14. What are the functions of the smooth endoplasmic reticulum? [hat are the functions of the rough endoplasmic reticulum? What proteins are produced on membrane bound ribosomes? 17. What proteins are produced on free ribosomes? 18. Describe the process of protein synthesis of a secretory protein starting with mRVA binding to free ribosome in the cytoplasm and ending- With properly folded protein in the lumen of the RER 19.How is it possible to modify the lipid composition of membrane? 20. If unfolded proteins accumulate; the cell will enter the unfolded protein response. What happens to trigger this process and what is the end result? 21. What happens to proteins 35 they move through the golgi? 22. State the direction of transport for each of the coated vesicles COPI COPII Clathrin 23. Describe the general construction of coated vesicle_Connective Tissue:

All animals possess the ability to secrete collagen, although some (humans) use it more extensively than others (bees). Collagen is both flexible and strong, allowing it to resist tensile stress while allowing freedom of movement. In many animals, collagen is concentrated in specialized connective tissues that make the most of its properties. Fibroblasts are the cells that create and define connective tissues. They secrete collagen and organize it into complex structures, much the way humans have devised machines for weaving and braiding plant and animal fibers into cloth and rope. Bone is a mineralized version of connective tissue forming the skeletons of many vertebrates, including humans. The cells responsible for adding calcium phosphate, the mineral in question are osteoblasts, derived from fibroblasts. There is a continuous spectrum of calcium phosphate content from completely elastic connective tissue to bones, with less mineralized tissue connecting them to muscles and each other.

Answer and Explanation: 1

Here are some things to know:

About Collagen

Collagen is a structural protein secreted by animals (defined as members of kingdom Animalia) taking the form of a long triple helix of three polypeptides. These proteins are organized into bundles called fibrils. Other proteins, notably fibronectin, link collagen to the plasma membranes and cytoskeletons of animal cells.

About the Extracellular Matrix

The extracellular matrix is a structure found outside the plasma (cell boundary) membranes of many eukaryotes. It is a protective sheath of molecules secreted by the cell, providing structural support and defense against parasites and other environmental hazards. This matrix is made from a variety of long fibers, some of protein and some of polysaccharides, anchored to the cell by specialized transmembrane (membrane-piercing) proteins. In animals, proteins are the dominant material for these fibers, while in other eukaryotes like true plants, polysaccharides dominate, but both are always present.

Proteins versus Polypeptides

Proteins are macromolecules composed of units called amino acids, which are able to form peptide bonds with each other. These bonds are covalent, and therefore very strong, forming polypeptide chains. A variety of noncovalent bonds join amino acids in the same or different polypeptides, giving proteins their shapes.

Polysaccharides are another type of macromolecule, formed out of sugar molecules, also known as saccharides. Each sugar can form covalent bonds with several others, making polysaccharides very strong and allowing them to have numerous side chains.