Assume that the binding of one molecule of epinephrine to a seven-transmembrane

Question

Assume that the binding of one molecule of epinephrine to a seven-transmembrane helix (7TM) receptor (also called the G protein-coupled receptor, or GPCR) results in the activation of 350 G_a subunits. In addition, suppose that each activated adenylyl cyclase catalyzes the conversion of 30 ATP molecules to cAMP per second. (Assume that each G protein activates a single unique adenylyl cyclase.) Calculate the number of moles of cAMP that are produced per second. Enter your answer to at least two significant figures. Note that these numbers are used for illustrative purposes only. The actual rates are different (and larger), and vary depending on type of receptor and regulatory proteins that increase or decrease the rate of the GTPase activity of the G_a subunit.

Explanation / Answer

1 Ga subunit ( called as G-protein ) activates 1 adenylyl cyclase molecule.

Since we have 350 subunits of Ga, so 350 units of adenylyl cyclase are available.

Since 1 adenylyl cyclase converts 30 ATP to cAMP per s,

so total cAMP produced per s = 350*30 = 10500 units of cAMP/s

NOTE : If actual number of moles of are asked, then divide the above term by Avogadro's number.

Related Questions

Navigate

• Browse (All)
• Browse A
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.