Number one, PKA basically activates enzymes which are responsible for breaking down glycogen into glucose. And then our cells can use the glucose to basically form ATP molecules. And for instance, if we're discussing muscle cells, if this is the membrane of a muscle cell, the ATP can then be used to contract that muscle. Another important function of PKA, among its many, many functions, is to activate special transcription factors that can basically go on, move into the nucleus of that cell and activate gene expression. And that can produce many important enzymes and proteins that must be used by that cell to carry out some type of physiological effect. Now, the next thing I'd like to focus on is how to actually terminate this specific epinephrine signal transduction pathway.