Histamine is a chemical substance released in inflammatory and allergic responses. The histamine H1 receptor is a G protein-coup
led receptor that activates phospholipase C in response to the binding of histamine. Place the items in the correct order to illustrate the process of histamine signal transduction from the H1 receptor. a.Calcium ions flow through the ligand-gated ion channel
b.Calcium ions activate a protein, leading to a cellular response
c.Calcium ion concentration increases in the cytosol.
d.binds to a ligand-gated ion channel in the ER membrane
e.Enzyme cleaves PIP2, forming DAG and lP3
D. IP3 binds to a ligand-gated ion channel in the ER membrane.
A. Calcium ions flow through the ligand-gated ion channel.
C. Calcium ion concentration increases in the cytosol.
B. Calcium ions activate a protein, leading to a cellular response.
Explanation:
The enzyme phospholipase C which cleaves PIP2 into DAG and IP3 Is activated by the G protein once the histamine signaling molecule is received. IP3 moves to the cytosol to bond to IP3 gated calcium channel in the Endoplasmic reticulum membrane allowing for influx of Ca++ from the Endoplasmic reticulum membrane to the cytosol prompting a cellular response. The histamine's signal transduction pathway allows for amplification and regulatation of a signal at different points
