dx 2 K 2Ⅹ at 1+(1+,) 0×4Yx+1 K K D+X4>DX relative binding mass action K constants D+Ⅹ 2 K K DX +X DDⅩ nk.pnd toT w synthesis/basal ate k DⅩ+P-t>Dx+P+nx k degradation/basal k rate choose elegant (dimensionless, relative) variables2K1 r K dk γ r Td0pt nk α 2K 4K 2σ 2K 3K 1σ γx 1 4 x2σ 2 )x 1 1 (1 σ 2 αx dt dx = = = = − + + + + = A dk X P nX 2 DX tk P 2 DX 2 DX 2 DX 4K 2X 2 DX * 2 DX 3K 2 D X 2 DX 2K 2 D X 2X 1K 2X ⎯⎯ →⎯ + ⎯⎯ →⎯ + + + ←⎯ →⎯ + ←⎯ →⎯ + ←⎯ →⎯ ←⎯ →⎯ relative binding constants ~ synthesis/basal rate ~ degradation/basal rate mass action choose elegant (dimensionless, relative) variables !