BIOL 1107 Study Guide - Quiz Guide: Phosphatase, Plasmodesma, Vasoconstriction

The insulin receptor is a
a. phosphatase.
b. kinase.
c. phosphodiesterase.
d. cAMP molecule.
e. G protein.

What do the following receptors all have in common: G protein-linked receptors, protein kinases, and ion channels?
Select one:
a. Conformational change once the ligand is bound
b. Ligand binding
c. Amplification of the signal
d. All of the above

Diacylglycerol
Select one:
a. activates G proteins.
b. hydrolyzes phosphatidyl inositol-bisphosphate.
c. is released from the cell as a paracrine-signaling molecule.
d. opens Ca2+ channels.
e. activates protein kinase C

Gap junctions
Select one:
a. permit metabolic cooperation among linked cells.
b. are present on few copies per cell.
c. contain membrane lined bridges.
d. are channels about 1. 5 mm in diameter.
e. allow large molecules and ions to pass rapidly between cells.

Smooth muscle cells in the airways relax while those in the blood vessels contract in response to the hormone epinephrine. What would you expect to be different in these two types of cells exposed to epinephrine?
Select one:
a. Presence of epinephrine receptors.
b. Exposure to epinephrine released by neighboring cells.
c. Activation of protein kinases.
d. Rate of metabolism.
e. Types of proteins expressed.

The second messenger IP3
Select one:
a. is released from the cell as a paracrine-signaling molecule.
b. hydrolyzes phosphatidyl inositol-bisphosphate.
c. activates protein kinase C.
d. opens Ca2+ channels.
e. activates G proteins.

1. What are the essential parts of a signaling pathway? 2. How could activating a transcription factor cause long-term cellular changes? 3. What roles can phosphorylation play in protein function? 4. What is the enzymatic activity of a kinase and of a phosphatase?