Exam 7: Interactions Between Cells and Their Environment

The opening in the center of a connexon that allows the passage of solutes between cells is called a(n)________.

Basement membranes contain Type IV collagen,a nonfibrillar collagen organized in a flattened network.The Type IV collagen trimer has some interspersed nonhelical segments.What property does this confer upon basement membranes?

You coat a Petri dish with fibronectin and proteoglycans and culture cells on the dish.The cells adhere to the dish.You repeat the experiment but this time add RGD tripeptides to the culture dish as the cells are added.The result of this experiment is an example of what biochemical process?

In an integrin,what structure is it that crosses the lipid bilayer?

What substance joins proteoglycans together into gigantic complexes called proteoglycan aggregates? These complexes can occupy very large volumes.

Type II collagen mutations alter the properties of cartilage tissue and are known to cause _______.

A new type of communication system has been discovered that consists of thin,highly elongated tubules capable of conducting cell-surface proteins,cytoplasmic vesicles and calcium signals from one cell to another.This system is referred to as ________.

Calcium ions form bridges between ________.

You are studying a plant and inject fluorescein,a fluorescent dye,into a single cell on the surface of the plant.After a brief period of time,the dye spreads to cells neighboring the injected cell.What do you conclude?

In which disease do individuals produce antibodies that bind to proteins present in hemidesmosmes? It causes the lower layer of the epidermis to lose attachment to the underlying basement membrane and thus to the underlying connective tissue layer of the dermis.The leakage of fluid into the space beneath the epidermis results in severe blistering of the skin.

Which tissues below are typically derived from the single-celled epithelium on the dorsal surface of a chick embryo after gastrulation?

Animals lacking the claudin-1 gene suffered from ___________.

The binding of lymphocytes to the endothelial lining of venules in peripheral lymph node frozen tissue sections could be blocked in what way? This demonstrated the existence of what kind of molecule?

Collagen fibrils are strengthened by covalent cross-links between _____ and ____ residues on adjacent collagen molecules.

During gap junction formation,connexons in apposing cells become tightly connected through extensive noncovalent interactions of __________.

What class of plant cell proteins facilitates plant cell growth by causing a localized relaxation of the cell wall,which allows the cell to elongate at that site in response to turgor pressure generated within the cell?

Which animal cell structure do plasmodesmata in plants most closely resemble?

You place mammary gland epithelial cells in culture and then treat them with enzymes that digest the surrounding extracellular matrix.What happens?

Focal adhesions ________.

Cell walls of young,undifferentiated plant cells must be able to grow along with the cells of which they are a part and thus exhibit extensibility.What are they known as?