Quiz #2 questions from slides Flashcards
True or False. Unlike conventional ion channels, individual
gap junction channels remain open continuously once they are formed.
False
True or False. A sheet of basal lamina underlies all epithelia
True
Certain bacteria secrete enzymes that can digest protein or
carbohydrate components of the basal lamina. Why do
you suppose they do so?
Tissue invasion
When you wake up in the morning and turn on the light, is dopamine release increased or decreased? How does
dopamine alter the neuronal activity in the retina?
Decrease, closes gap junction
Define: Cell growth that is dependent on
attachment to a substrate.
Anchorage dependance
Define: Cytoplasmic tyrosine kinase that is present at cell-matrix junctions in association with
cytoplasmic tails of integrins.
FAK
Hemichannels usually kept In the closed or
open conformation?
Closed
You are interested in integrin activation and perform mutagenesis studies on integrin. You find a mutant form of integrin which you call int-act, because the int-act mutation causes the extracellular domain to exist always in an unfolded state regardless of the presence or absence of ligand. When you determine the sequence of int-act, you find that the
mutation is in the intracellular domain of integrin. Explain
how this intracellular mutation could affect the conformation of the extracellular domain of integrin.
Inside-outside signalling
-Change on inside = conformation change on outside
-Bidirectional communication
Define: Anchoring junctions that connects actin filaments in one cell to those in the next cell.
Adherens junctions
True or False. Cadherins promote cell-cell interactions by binding to cadherin molecules of the same subtype on adjacent cells
True
Overproduction of cadherins such as E-cadherin …
a. is often found in cancers originating from epithelia.
b. is induced by the transcription regulatory protein Twist.
c. induces epithelial–mesenchymal transition.
d. leads to stronger cell–cell adhesion.
e. All of the above
D
