128
Variables and Constants
|
Φ |
Number of photoisomerizations |
|
R |
Number of activated rhodopsin molecules |
|
E |
Number of activated PDE molecules |
|
cG |
cGMP concentration in outer seg. (μM) |
|
c |
Calcium concentration in outer seg. (μM) |
|
Cb |
Buffered calcium concentration in outer seg. (μM) |
|
cGctark ~ 2 μM. |
Dark cGMP level |
|
ncG = 2.201 |
CNG channel activation Hill coeff. |
|
Tr = 0.416 S |
Rhodopsin deactivation time const. |
|
υrp = 1734.72 s^1 |
Photopigment activation rate |
|
te = 1.195 s |
PDE inactivation time const. |
|
Amax = 4.461 μM∕s |
Maximum cGMP synthesis rate |
|
Kca = 0.219 μM |
Half-activation level of guanylate cyclase by Ca |
|
nca = 2.855 |
Ca activated guanylate cyclase Hill coeff. |
|
βdaτk = 0.136 S-ɪ |
cGMP hydrolysis rate in darkness |
|
[3E = 1.68 X 10^5 s“ 1 |
PDE dependent cGMP hydrolysis rate |
|
b = 0.780 μMs-1pA~1 |
Photocurrent to Ca flux |
|
Jd = 72.296 pA |
Photocurrent model dark current |
|
7c = 99.67 s-1 |
Ca exchanger extrusion rate |
|
Cmin = 0.005 μM |
Minimum outer segment Ca level |
|
kl = 0.166 μM^1s'1 |
Ca buffer binding rate |
|
et = 394.58 μM |
Total Ca buffer concentration |
|
k2 = 2.350 s’1 |
Ca buffer unbinding rate |