My Dictionary #4

This will be my final post on the definitions on new, interesting, unfamiliar terms.

1. Nitric Oxide - This is a signaling molecule that is paracrine in type. It crosses the plasma membrane by binding to a receptor and affects enzyme activity. Just like the G protein, nitric oxide targets the enzyme, guanylyl cyclase, and thus, makes cyclic GMP. In the body, it affects smooth muscles and blood vessels.

2. Eicosanoids -These are lipid signaling molecules that include prostaglandins, prostacyclin, thromboxanes, and leukotrienes. They break down rapidly.

3. Ligand-gated channel - Unlike the voltage-gated channel, these channels do not open based on voltage, but they are activated or opened because of some signaling molecule (ligand).