Table 5 Parameter values of the CO2 transport model.
From: Physiological responses of Daphnia pulex to acid stress
Symbol | Value | Unit | Description |
|---|---|---|---|
L | 2.38 | mm | Length of exchange coordinate |
A ca | 7.57 | mm2 | Exchange surface area of the inner carapace cuticle |
A tr | 5.34 | mm2 | Exchange surface area of the trunk cuticle |
Δxca | 0.001 | mm | Thickness of the inner carapace cuticle |
Δxtr | 0.002 | mm | Thickness of the trunk cuticle |
| 0.022 | mm3 s-1 | Perfusion rate |
| 0.7 | mm3 s-1 | Medium flow rate |
ν b | 0.168 | mm s-1 | Hemolymph flow velocity, backward direction |
ν f | 0.149 | mm s-1 | Hemolymph flow velocity, forward direction |
ν m | 1.8 | mm s-1 | Medium flow velocity |
| 0.0071 | nmol s-1 | Whole-animal CO2 production rate |
| 0.3682 | nmol mm-3 kPa-1 | Physical solubility of CO2 in medium and hemolymph |
K | 2.10 × 10-6 | nmol s-1 mm-1 kPa-1 | Krogh's diffusion constant for CO2 in chitin |
K' 1 | 10-6.325 | M | Dissociation equilibrium constant of CO2 |
K' 2 | 10-10.47 | M | Dissociation equilibrium constant of |
K' A | 10-8.18 | M | Dissociation equilibrium constant of the NB buffer |
K' w | 10-14 | M | Dissociation equilibrium constant of water |
k 1 | 0.022 | s-1 | Rate constant for CO2 hydration |
k 2 | 1010 | M-1 s-1 | Rate constant for the protonation of |
k 3 | 5500 | M-1 s-1 | Rate constant for the reaction of CO2 with OH- |
k -3 | 1.1 × 10-4 | s-1 | Rate constant for: |
k 4 | 1010 | M-1 s-1 | Rate constant for the protonation of the NB buffer |
μ | 1 | Acceleration factor for CO2/ | |
ρ | 0.5 | Fraction of | |
φ | 0.2 | Fraction of CO2 excreted into the outer HL lacuna | |
γ H | 0.797 | Hydrogen activity coefficient | |
C A | 3.6 | nmol mm-3 | Concentration of the NB buffer in the hemolymph |
P in | 0.035 | kPa | Inspiratory CO2 partial pressure |
pHin | 8.0 | pH of the inspired medium | |
[ | 0.6 | nmol mm-3 | Bicarbonate concentration of the inspired medium |
