Refer to the two figures below. The receptor portions of two signal transduction pathways are shown.The two mechanisms underlying these pathways are similar in that they both involve
A) gated ion channels.
B) activating a kinase as part of the signaling process.
C) a protein binding to the same signal molecule.
D) a protein conformational change in response to a signal molecule.
E) an ion serving as a second messenger.

Question

Refer to the two figures below.  The receptor portions of two signal transduction pathways are shown.The two mechanisms underlying these pathways are similar in that they both involve
A) gated ion channels. 
B) activating a kinase as part of the signaling process. 
C) a protein binding to the same signal molecule. 
D) a protein conformational change in response to a signal molecule. 
E) an ion serving as a second messenger.

Quizplus · Accepted Answer

Both pathways involve a protein conformational change in response to a signal molecule binding to a receptor. In the first pathway, the conformational change occurs in the G protein, which then activates an effector protein. In the second pathway, the conformational change occurs in the receptor itself, which then activates an intracellular signal transduction cascade.

Refer to the Two Figures Below