Which of the following is responsible for initiating a signal transduction pathway?

Binding of a signaling molecule to which type of receptor leads directly to a change in the distribution of substances on opposite sides of the membrane?

a. Intracellular receptor

b. G protein-coupled receptor

c. Phosphorylated receptor tyrosine kinase dimer

d. Ligand-gated ion channel

What does it mean to say that a signal is transduced?

a. The signaling molecule enters the cell directly and elicits a cellular response.

b. The signal is generated by the production of proteins.

c. The physical form of the signal changes between the outside of the cell and the inside.

d. The signal is amplified.