Many G Protein-Coupled Receptors Contain Seven Transmembrane α-Helical Domains

question 40

Multiple Choice

Many G protein-coupled receptors contain seven transmembrane α-helical domains. If the amino terminus of such a protein is located on the extracellular side of the membrane, where would a coupled G protein most likely interact with this receptor?

• A) at the amino end
• B) at the carboxyl end
• C) along the exterior margin
• D) at the loop between helix 5 and helix 6

---

Definitions:

Opiate Drugs

A classification of narcotics derived from the opium poppy plant, often used for pain relief but also associated with a high potential for addiction and abuse.

Endorphins

Naturally occurring peptides in the brain that act as neurotransmitters and have pain-relieving properties similar to morphine.

Agitation

A state of anxiety or nervous excitement, often manifesting as restless or tumultuous behavior.

Anxiety

A feeling of worry, nervousness, or unease, typically about an imminent event or something with an uncertain outcome.