Final Exam - Glycocalyx and ECM Flashcards
Where is glycocalyx found?
extracellular surface of the cells; membrane decoration
What are the functions of glycocalyx?
- protective barrier from bacterial invasion
- immune recognition of self
- intercellular adherance
How does glycocalyx execute its function of immune recognition of self?
specific glycoproteins deflect immune system from normal cells
When is glycocalyx involved in intercellular adherance?
- early adhesion events during tissue formation
- blood clot formation
What is the structure of a glycoprotein?
a membrane protein with a polysaccharide attached to it
True or False: there is only one type of glycoprotein
False: different cell types have different polysaccharides linked to them
What is the structure of a glycolipid?
a glycoprotein with a lipid connected to the polysaccharides
How does the avian flu take advantage of glycocalyx?
specific glycoproteins act as an attachment site for H5N1
Where does H5N1 attach in birds?
in the mid region of the lungs
Where does H5N1 attach in humans?
deep in the lungs
What is glycocalyx made up of?
glycoproteins and glycolipids
What is the difference between O, A, and B blood antigens?
A and B are both similar to O, but they have different sugars attached to them
What attaches to glycocalyx in the intestines?
digestive enzymes
What is the structure of M cells?
they are shorter and sparser making them more susceptible to salmonella
Where are most animal cells embedded in?
the extracellular matrix
What is the structure of the extracellular matrix?
basement membrane and interstitial matrix
What tissue type is the extracellular matrix most prominent in?
connective tissue
What are the components of the extracellular matrix in connective tissue?
Glycose amino glycans (GAGS), hyaluronic acid, collagen, elastic fibers
What is the structure of a glycose amino glycans?
proteoglycans - protein core with carbohydrate chains
What are the functions of proteoglycans?
- attract water, provide a well hydrated matrix
- withstand compressive forces
- cell migration during development and repair
- filtration function in certain tissues
- binding sites for other molecules
- attachment to fibrous elements
What is the function of hyaluronic acid?
pulls water into the extracellular matrix in the dermis plumping up the skin
What is collagen?
a family of proteins, fibers made of collagen molecules
Where is collagen synthesized?
inside the cell
Where is collagen assembled?
extracellularly
What is important about the arrangement of collagen fibers?
the arrangement of fibers determines forces that can be tolerated by tissue
What are elastic fibers?
network of elastin molecules
What do elastic fibers provide?
tissue elasticity; especially in the skin, aorta and lung
What does over production of hyaluronic acid cause?
wrinkly skin, especially in shar peis, makes the skin too plump
What is the cause of Ehlers-Danlos syndrome?
defect in collagen synthesis
How can Ehlers-Danlos syndrome present?
cutis hyperelastica - stretchy skin
What can excessive elastase production cause?
emphysema
