Chapter 7 Flashcards
Do cells interact with the extracellular environment?
Yes
What is the glycolyx?
Carbohydrate projections on outer surface of the plasma membrane
Roles of the glycolyx?
- mediator of cell-cell and cell-substratum interactions
- mechanical projection
- barrier to molecular movement toward plasma membrane
- regulatory factor binding site
ECM protein texture:
Fibrous
What is the best to find extra cellular matrices?
The basement membrane
What does the basement membrane surround?
Muscles, nerves, and fat cells 
What are collagens?
A family of fibrous glycol proteins known for their high tensile strength the function exclusively as part of the extra cellular matrix
What is the most abundant protein in the human body?
Collagen
A collagen molecule is made up of what?
Triple helix of three helical alpha chains, known as trimers
What is collagen produced by?
Fibroblasts, smooth muscle, and epithelial cells 
What is the corneal stroma?
Layers of collagen fibres of uniform diameter and spacing arranged at right angles
Define: Proteoglycans
Protein – polysaccharide complex, with a core protein attached to glycosaminoglycans
Where are proteoglycans common?
In basement membranes and cartilage
What is fibronectin?
It binds to cell receptors to attach cell to the ECM, used for cell adhesion and shape determination
What is laminin?
It can influence the cells potential for migration, growth, and differentiation. Role in development of neuronal outgrowth
What are integrins?
Family of membrane proteins unique to animals, in cells not the ECM
What are integrins composed of?
Two membrane spanning polypeptide chains, an alpha and a beta chain
Changes in integrins are driven by what?
Divalent metal ions
What are the two major activities of integrins?
- Adhesion of cells to ECM or two other cells
- Transmission of signals between external environment and cell interior
Intracellularly, integrins binds to what?
Ligands like talin (Inside out signalling)
What are outside in signals?
Different integrins find different ECM components, can induce confirmational change in Talin
What is the function of outside in signals?
Can influence cell differentiation, motility, growth, and cell survival
What is focal adhesion?
Cultured cells are anchored to surface of the dish only at scattered, discrete sites
Focal adhesion function:
Play a key role in cell and heating and locomotion
