| | Name | Initial Conc. (uM) | Volume (fL) | Buffered |
| 1 | Gbg | 0 | 1000 | No |
| | The Gbetagamma dimer. |
| 2 | GDP.Ga | 0 | 1000 | No |
| | The inactive GDP-bound form of Gs alpha. |
| 3 | GDP.Gabc | 1 | 1000 | No |
| | The resting state of Gs: GDP bound to trimer. From Pang and Sternweis JBC 265:30 18707-12 1990 we get conc est 1.6 uM to 0.8 uM. We'll use 1 uM. |
| 4 | L | 0 | 1000 | Yes |
| | This ligand could be any of several which bind to the beta adrenergic receptor and other G-protein coupled receptors which activate AC. For the sake of argument, call it isoproterenol. |
| 5 | L.R | 0 | 1000 | No |
| | Ligand.Receptor complex |
| 6 | L.R.GDP.Gabc | 0 | 1000 | No |
| | This is the ternary complex, where all the action happens. There are actually a lot more steps here, including a final step where the GTP binds the L.R.Ga complex and causes the release of GTP.Ga from the L.R. For simplicity this is excluded. |
| 7 | R | 0.0833 | 1000 | No |
| | A typical number of receptors per cell is about 50000. |
| 8 | R.GDP.Gabc | 0 | 1000 | No |
| | Fraction of R.GDP.Gabc is about 50% of total R, from Fay et al. Biochemistry 30:5066-5075(1991) Since this is not the same receptor, this value is a bit uncertain. |
