If a Ligand Binds to a G Protein-Coupled Receptor but the Normal

question 127

Multiple Choice

If a ligand binds to a G protein-coupled receptor but the normal exchange of GDP for GTP on the associated G protein does not take place, what will happen in the cell?

• A) Cell responses that depend on an activated effector protein will not occur.
• B) GDP binding will cause a conformational change in the G protein-coupled receptor.
• C) The GDP-bound subunit will travel through the lipid bilayer.
• D) The ligand will not be released from the G protein-coupled receptor.
• E) Inactive G protein will be activated.

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Definitions:

Synapses

The junctions through which neurons communicate with other neurons, muscle cells, or gland cells.

Absolute Thresholds

The minimum stimulus energy needed to detect a particular stimulus 50% of the time.

General Tendency

A common or widespread inclination, pattern, or trend among people or phenomena.

Absolute Threshold

The minimum intensity of a stimulus that one can detect at least 50% of the time, which varies from one individual to another and for different senses.