\(\newcommand{\p}[1]{\frac{\partial }{\partial #1}}\) \(\newcommand{\pp}[2]{\frac{\partial #1}{\partial #2}}\) \(\newcommand{\dd}[2]{\frac{d #1}{d #2}}\) \(\newcommand{\h}{\frac{1}{2}}\) \(\newcommand{\op}[1]{\operatorname{#1}}\)

8.7.3.8. Macromolecular parameterization of growth

To enable the macromolecular parameterization of phototrophic growth, define DARWIN_MACROMOLECULAR_GROWTH in DARWIN_OPTIONS.h. Phytoplankton need to have flexible nitrogen, phosphorus and iron quotas, so also define DARWIN_ALLOW_NQUOTA, DARWIN_ALLOW_PQUOTA and DARWIN_ALLOW_FEQUOTA.

The macromolecular growth parameterization is based on [SID+26]. In order to parameterize the growth rate as a function of elemental quotas, we assume that the available carbon, nitrogen, phosphorus and iron in the organism are allocated optimally to macromolecular pools to achieve maximum growth rate, \(P_{\mathrm{C}}\), at every instant. To determine this growth rate, the macromolecular requirements are expressed as a function of growth rate. The available quota of each element then provides a constraint on the achievable growth rate which can be obtained by solving for \(P_{\mathrm{C}}\) as a function of the required quota. The realized growth rate is the smallest of these solutions, the one obtained from the most limiting quota.

The assumed macromolecular pools and fluxes between them are shown in Figure 8.24.

Figure 8.24 Macromolecular pools and fluxes

They imply the following elemental quota requirements:

(8.67)\[ \begin{align}\begin{aligned}Q_{\mathrm{C}}^{\mathrm{ess}} &= Q_{\mathrm{C}}^{\mathrm{Chl}} + Q_{\mathrm{C}}^{\mathrm{Pro}} + Q_{\mathrm{C}}^{\mathrm{RNA}} + Q_{\mathrm{C}}^{\mathrm{DNA}} + Q_{\mathrm{C}}^{\mathrm{Thy}} + Q_{\mathrm{C}}^{\mathrm{Other}}\\Q_{\mathrm{N}}^{\mathrm{ess}} &= Q_{\mathrm{N}}^{\mathrm{Chl}} + Q_{\mathrm{N}}^{\mathrm{Pro}} + Q_{\mathrm{N}}^{\mathrm{RNA}} + Q_{\mathrm{N}}^{\mathrm{DNA}}\\Q_{\mathrm{P}}^{\mathrm{ess}} &= Q_{\mathrm{P}}^{\mathrm{Thy}} + Q_{\mathrm{P}}^{\mathrm{RNA}} + Q_{\mathrm{P}}^{\mathrm{DNA}} + Q_{\mathrm{P}}^{\mathrm{Other}}\\Q_{\mathrm{Fe}}^{\mathrm{ess}} &= Q_{\mathrm{Fe}}^{\mathrm{Pro\_Pho}}\end{aligned}\end{align} \]

Any quotas beyonds these essential values will be distributed between a store and an excess that is used to regulate uptake,

(8.68)\[ \begin{align}\begin{aligned}Q_{\mathrm{C}} &= Q_{\mathrm{C}}^{\mathrm{ess}} + Q_{\mathrm{C}}^{\mathrm{Stor}} + Q_{\mathrm{N}}^{\mathrm{Stor}} Y^{\mathrm{C}:\mathrm{N}}_{\mathrm{Nsto}} + Q_{\mathrm{C}}^{\mathrm{exc}}\\Q_{\mathrm{N}} &= Q_{\mathrm{N}}^{\mathrm{ess}} + Q_{\mathrm{N}}^{\mathrm{Stor}} + Q_{\mathrm{N}}^{\mathrm{exc}}\\Q_{\mathrm{P}} &= Q_{\mathrm{P}}^{\mathrm{ess}} + Q_{\mathrm{P}}^{\mathrm{Stor}} + Q_{\mathrm{P}}^{\mathrm{exc}}\\Q_{\mathrm{Fe}} &= Q_{\mathrm{Fe}}^{\mathrm{ess}} + Q_{\mathrm{Fe}}^{\mathrm{Stor}} + Q_{\mathrm{Fe}}^{\mathrm{exc}}\end{aligned}\end{align} \]

The molar fractions of the macromolecules are a function of light, temperature, and nutrient uptake. To find the required chlorophyll quota, \({Q_{\mathrm{C}}^{\mathrm{Chl}}}\) , consider the net change of cellular carbon quota from photosynthesis, growth and maintainance:

\[Q_{\mathrm{C}}^{\mathrm{Chl}} P_{\mathrm{Chl}}(I) - (1 + E) P_{\mathrm{C}} - m \;.\]

The chlorophyll-specific photosynthesis rate is a function of the photosynthetically active radiation, \(I\),

\[P_{\mathrm{Chl}}(I) = S_{\mathrm{f}} V^{\max}_{\mathrm{I}} f_{\mathrm{I}}(I) \quad\text{with}\quad f_{\mathrm{I}}(I) = 1 - e^{-A_{\mathrm{I}}I} \;,\]

By assuming fixed carbon quota, the chlorophyll quota required for growth rate \(P_{\mathrm{C}}\) at given light is:

(8.69)\[Q_{\mathrm{C}}^{\mathrm{Chl}} = \frac{m + (1+E) P_{\mathrm{C}}}{P_{\mathrm{Chl}}(I)} \;.\]

The photosynthetic protein pool is assumed to be proportional to chlorophyll,

\[Q_{\mathrm{C}}^{\mathrm{Pro\_Pho}} = A_{\mathrm{Pho}} Q_{\mathrm{C}}^{\mathrm{Chl}} \;.\]

The biosynthetic protein pool to growth rate, with a temperature dependence (only DARWIN_TEMP_VERSION 2 is supported)

\[Q_{\mathrm{C}}^{\mathrm{Pro\_Bio}} = A_{\mathrm{Bio}} P_{\mathrm{C}} / f^{\mathrm{mm}}(T) \;.\]

Total proteins also include a base pool of ‘other’ protein,

\[Q_{\mathrm{N}}^{\mathrm{Pro}} = Q_{\mathrm{N}}^{\mathrm{Pro\_Other}} + Q_{\mathrm{N}}^{\mathrm{Pro\_Pho}} + Q_{\mathrm{N}}^{\mathrm{Pro\_Bio}} \;.\]

Here, the elemental quotas of the pools are related as

\[ \begin{align}\begin{aligned}Q_{\mathrm{N}}^{\mathrm{Pro\_Pho}} &= Q_{\mathrm{C}}^{\mathrm{Pro\_Pho}}/Y^{\mathrm{C}:\mathrm{N}}_{\mathrm{Pro}}\\Q_{\mathrm{N}}^{\mathrm{Pro\_Bio}} &= Q_{\mathrm{C}}^{\mathrm{Pro\_Bio}}/Y^{\mathrm{C}:\mathrm{N}}_{\mathrm{Pro}} \;.\end{aligned}\end{align} \]

RNA pools depend on protein pools and growth rate, again with a temperature dependence,

\[Q_{\mathrm{P}}^{\mathrm{RNA}} = A^{\mathrm{P}}_{\mathrm{RNA}} Q_{\mathrm{C}}^{\mathrm{Pro}} P_{\mathrm{C}} / f^{\mathrm{mm}}(T) + Q_{\mathrm{P,min}}^{\mathrm{RNA}}\]

with

\[Q_{\mathrm{C}}^{\mathrm{Pro}} = Y^{\mathrm{C}:\mathrm{N}}_{\mathrm{Pro}} Q_{\mathrm{N}}^{\mathrm{Pro}} \;.\]

We find the other cell component from the following stoichiometric relations:

\[ \begin{align}\begin{aligned}Q_{\mathrm{N}}^{\mathrm{Chl}} &= Y^{\mathrm{N}:\mathrm{C}}_{\mathrm{Chl}} Q_{\mathrm{C}}^{\mathrm{Chl}}\\Q_{\mathrm{P}}^{\mathrm{Thy}} &= Y^{\mathrm{P}}_{\mathrm{Thy}} Q_{\mathrm{C}}^{\mathrm{Chl}}\\Q_{\mathrm{N}}^{\mathrm{RNA}} &= Q_{\mathrm{P}}^{\mathrm{RNA}}/Y^{\mathrm{P}:\mathrm{N}}_{\mathrm{RNA}}\\Q_{\mathrm{C}}^{\mathrm{RNA}} &= Y^{\mathrm{C}:\mathrm{N}}_{\mathrm{RNA}} Q_{\mathrm{N}}^{\mathrm{RNA}}\\Q_{\mathrm{C}}^{\mathrm{Thy}} &= Y^{\mathrm{C}:\mathrm{P}}_{\mathrm{Plip}} Q_{\mathrm{P}}^{\mathrm{Thy}}\\Q_{\mathrm{Fe}}^{\mathrm{Pro\_Pho}} &= Y^{\mathrm{Fe}:\mathrm{N}}_{\mathrm{Pho}} Q_{\mathrm{N}}^{\mathrm{Pro\_Pho}}\\Q_{\mathrm{N}}^{\mathrm{Pro\_Other}} &= Q_{\mathrm{C}}^{\mathrm{Pro\_Other}}/Y^{\mathrm{C}:\mathrm{N}}_{\mathrm{Pro}}\\Q_{\mathrm{N,min}}^{\mathrm{RNA}} &= Q_{\mathrm{P,min}}^{\mathrm{RNA}}/ Y^{\mathrm{P}:\mathrm{N}}_{\mathrm{RNA}}\\Q_{\mathrm{C,min}}^{\mathrm{RNA}} &= Y^{\mathrm{C}:\mathrm{N}}_{\mathrm{RNA}} Q_{\mathrm{N,min}}^{\mathrm{RNA}}\\Q_{\mathrm{N}}^{\mathrm{DNA}} &= Q_{\mathrm{C}}^{\mathrm{DNA}}/Y^{\mathrm{C}:\mathrm{N}}_{\mathrm{DNA}}\\Q_{\mathrm{P}}^{\mathrm{DNA}} &= Y^{\mathrm{P}:\mathrm{N}}_{\mathrm{RNA}} Q_{\mathrm{N}}^{\mathrm{DNA}} \;,\end{aligned}\end{align} \]

These cellular balances for each element, without the storage component, yield trinomial equation for growth rate, which solve numerically

\[Q_{X}^{\mathrm{ess}} = Q_{X}^{(0)} + Q_{X}^{(1)} P_{\mathrm{C}} + Q_{X}^{(2)} P_{\mathrm{C}}^2 \;.\]

By equating these to the actually available quotas, we obtain maximum growth rates for each quota limitation, \(P_{\mathrm{C}}^X\). The realized growth rate is the smallest,

\[P_{\mathrm{C}} = \min\left( P_{\mathrm{C}}^{\mathrm{N}}, P_{\mathrm{C}}^{\mathrm{P}}, P_{\mathrm{C}}^{\mathrm{Fe}}, P_{\mathrm{C}}^{\mathrm{C}} \right) \;.\]

8.7.3.8.1. No-growth, non-zero chlorophyll case

When one of the nutrient-limited growth-rate equations does not have a positive solution, the growth rate is zero. In this case, it is assumed that the macromolecular requirements for Chlorophyll in the first part of this section are still valid (but for \(P_{\mathrm{C}}=0\)). We can then compute the maximum amount of chlorophyll possible for each limiting nutrient,

\[ \begin{align}\begin{aligned}Q_{\mathrm{C}}^{\mathrm{Chl,N}} &= \frac{ Q_{\mathrm{N}} - Q_{\mathrm{N}}^{\text{no-Chl}} } { Y^{\mathrm{N}:\mathrm{C}}_{\mathrm{Chl}} + A_{\mathrm{Pho}}/Y^{\mathrm{C}:\mathrm{N}}_{\mathrm{Pro}} }\\Q_{\mathrm{C}}^{\mathrm{Chl,P}} &= \frac{ Q_{\mathrm{P}} - Q_{\mathrm{P}}^{\text{no-Chl}} }{ Y^{\mathrm{P}}_{\mathrm{Thy}} }\\Q_{\mathrm{C}}^{\mathrm{Chl,Fe}} &= \frac{ Q_{\mathrm{Fe}} } { A_{\mathrm{Pho}} Y^{\mathrm{Fe}:\mathrm{N}}_{\mathrm{Pho}} /Y^{\mathrm{C}:\mathrm{N}}_{\mathrm{Pro}} }\end{aligned}\end{align} \]

where

\[ \begin{align}\begin{aligned}Q_{\mathrm{N}}^{\text{no-Chl}} &= Q_{\mathrm{N,min}}^{\mathrm{RNA}} + Q_{\mathrm{N}}^{\mathrm{DNA}} + Q_{\mathrm{N}}^{\mathrm{Pro\_Other}}\\Q_{\mathrm{P}}^{\text{no-Chl}} &= Q_{\mathrm{P,min}}^{\mathrm{RNA}} + Q_{\mathrm{P}}^{\mathrm{DNA}} + Q_{\mathrm{P}}^{\mathrm{Other}}\end{aligned}\end{align} \]

are the essential quotas for zero growth. (Without growth, no iron is required).

The carbon requirements also imply a maximum chlorophyll value for the zero growth case,

\[Q_{\mathrm{C,max}}^{\mathrm{Chl}} = \frac{m}{V^{\min}_{\mathrm{I}}}\]

where

\[ \begin{align}\begin{aligned}V^{\min}_{\mathrm{I}} &= m \frac{ 1 + A_{\mathrm{Thy}} + A_{\mathrm{Pho}} } { 1-Q_{\mathrm{C}}^{\mathrm{const}} }\\Q_{\mathrm{C}}^{\mathrm{const}} &= Q_{\mathrm{C}}^{\mathrm{Pro\_Other}} + Q_{\mathrm{C,min}}^{\mathrm{RNA}} + Q_{\mathrm{C}}^{\mathrm{DNA}} + Q_{\mathrm{C}}^{\mathrm{Other}} \;.\end{aligned}\end{align} \]

The realized amount of chlorophyll is the one compatible with all these, and the constraint from carbon requirement,

\[Q_{\mathrm{C}}^{\mathrm{Chl}} = \min\bigl( Q_{\mathrm{C}}^{\mathrm{Chl,N}}, Q_{\mathrm{C}}^{\mathrm{Chl,P}}, Q_{\mathrm{C}}^{\mathrm{Chl,Fe}}, Q_{\mathrm{C}}^{\mathrm{Chl}\max} \bigr) \;.\]

8.7.3.8.2. No-chlorophyll case

When even the minimum quota requirements for chlorophyll are not met, the available quotas are divided evenly between the pools needed for chlorophyll,

\[ \begin{align}\begin{aligned}Q_{\mathrm{N}}^{\mathrm{RNA}} &= f \cdot Q_{\mathrm{N,min}}^{\mathrm{RNA}}\\Q_{\mathrm{N}}^{\mathrm{DNA\_actl}} &= f \cdot Q_{\mathrm{N}}^{\mathrm{DNA}}\\Q_{\mathrm{P}}^{\mathrm{RNA}} &= f \cdot Q_{\mathrm{P,min}}^{\mathrm{RNA}}\\Q_{\mathrm{P}}^{\mathrm{DNA\_actl}} &= f \cdot Q_{\mathrm{P}}^{\mathrm{DNA}}\end{aligned}\end{align} \]

where

\[f = \min\left( \frac{Q_{\mathrm{N}}}{Q_{\mathrm{N}}^{\text{no-Chl}}}, \frac{Q_{\mathrm{P}}}{Q_{\mathrm{P}}^{\text{no-Chl}}} \right) \;.\]

Any excess (of the non-limiting element) goes to the nitrogen protein or phosphorus ‘other’ pool,

\[ \begin{align}\begin{aligned}Q_{\mathrm{N}}^{\mathrm{Pro}} &= \min\left( Q_{\mathrm{N}} - Q_{\mathrm{N}}^{\mathrm{RNA}} - Q_{\mathrm{N}}^{\mathrm{DNA\_actl}}, Q_{\mathrm{N}}^{\mathrm{Pro\_Other}} \right)\\Q_{\mathrm{P}}^{\mathrm{Other\_actl}} &= \min\left( Q_{\mathrm{P}} - Q_{\mathrm{P}}^{\mathrm{RNA}} - Q_{\mathrm{P}}^{\mathrm{DNA\_actl}}, Q_{\mathrm{P}}^{\mathrm{Other}} \right) \;.\end{aligned}\end{align} \]

The essential quotas are then recomputed with these reduced pools.

8.7.3.8.3. Storage and uptake regulation

Nutrient storage is computed from excess quota beyond essential. Nitrogen storage is limited by a fixed maximum and the required carbon quota for the store,

\[Q_{\mathrm{N}}^{\mathrm{Stor}} = \min\left( Q_{\mathrm{N}} - Q_{\mathrm{N}}^{\mathrm{ess}}, Q_{\mathrm{N,max}}^{\mathrm{Sto}}, \frac{ Q_{\mathrm{C}} - Q_{\mathrm{C}}^{\mathrm{ess}} } { Y^{\mathrm{C}:\mathrm{N}}_{\mathrm{Nsto}} } \right) \;.\]

For phosphorus and iron, the quotas are limited rather than the store,

\[ \begin{align}\begin{aligned}Q_{\mathrm{P}}^{\mathrm{Stor}} &= \min\left( Q_{\mathrm{P}}, Q_{\mathrm{P}}^{\mathrm{max}} \right) - Q_{\mathrm{P}}^{\mathrm{ess}}\\Q_{\mathrm{Fe}}^{\mathrm{Stor}} &= \min\left( Q_{\mathrm{Fe}}, Q_{\mathrm{Fe}}^{\mathrm{max}} \right) - Q_{\mathrm{Fe}}^{\mathrm{ess}} \;.\end{aligned}\end{align} \]

Excess nitrogen quota that cannot be stored leads to a reduction in uptake via an additional multiplicative regulation term in \(U^{\mathrm{NO3}}\),

\[\mathrm{reg}^{\mathrm{mm}}_{\mathrm{N}} = \frac{1.1 (Q_{\mathrm{N}}^{\mathrm{ess}} + Q_{\mathrm{N}}^{\mathrm{Stor}}) - Q_{\mathrm{N}}} {0.1 (Q_{\mathrm{N}}^{\mathrm{ess}} + Q_{\mathrm{N}}^{\mathrm{Stor}})} \;,\]

and similar for phosphorus and iron.

Table 8.38 Traits of the macromolecular growth model

symbol	trait	param	default	units	description
\(E\)	ECo2Prod	a_ECo2Prod	0.774	dimensionless	respiratory cost of biosynthesis
\(m\)	maintConsum	a_maintConsum	0.393/day	1/s	maintenance respiration rate
\(V^{\max}_{\mathrm{I}}\)	VI_max	a_VI_max	277/day	molC/s / (molC in Chl)	per-chlorophyll maximum photosynthesis rate
		b_VI_max	0
\(A_{\mathrm{I}}\)	A_I	a_A_I	0.008633641	m2s/μmol	coefficient characterizing the absorption cross section
\(S_{\mathrm{f}}\)	Sf		1.0	unitless	enhancement of photosynthesis due to size
\(A_{\mathrm{Pho}}\)	A_pho	a_A_pho	16.0	molC / (molC in Chl)	A constant of proportionality
\(A_{\mathrm{Bio}}\)	A_bio	a_A_bio	0.2711*day	molC / (molC/s)	constant for variable part of biosynthesis protein
\(A^{\mathrm{P}}_{\mathrm{RNA}}\)	AP_RNA	a_AP_RNA	0.00423*day	molP / (molC/s)	constant for variable part of RNA
\(Q_{\mathrm{C}}^{\mathrm{Other}}\)	QC_other	a_QC_other	0.0182	molC / molC	constant pool of structural lipids and carbs
\(Q_{\mathrm{C}}^{\mathrm{Pro\_Other}}\)	QC_pro_other	a_QC_pro_other	0.24	molC / molC	constant pool of essential proteins
\(Q_{\mathrm{P}}^{\mathrm{Other}}\)	QP_other	a_QP_other	6.5344E-4	molP / molC	constant part of phosphorus
\(Q_{\mathrm{P,min}}^{\mathrm{RNA}}\)	QP_RNA_min	a_QP_RNA_min	2.23E-4	molP / molC	minimum RNA in the cell
\(Q_{\mathrm{C}}^{\mathrm{DNA}}\)	QC_DNA	a_QC_DNA	9.41E-4	molC / molC	constant part of DNA
\(Q_{\mathrm{N,max}}^{\mathrm{Sto}}\)	QN_sto_max	a_QN_sto_max	0.035	molN / molC	maximum nitrogen storage
		b_QN_sto_max	0
\(Q_{\mathrm{P}}^{\mathrm{max}}\)	Qp_max	a_Qp_max	0.0052	molP / molC	maximum phosphorus quota
		b_Qp_max	0
\(Q_{\mathrm{Fe}}^{\mathrm{max}}\)	Qfe_max	a_Qfe_max	2.436E-4	molFe / molC	maximum iron quota
		b_Qfe_max	0
\(Y^{\mathrm{C}:\mathrm{P}}_{\mathrm{Plip}}\)	Y_CP_Plip	a_Y_CP_Plip	40.0	molC / molP	C/P molar ratio of thylakoid membrane
\(Y^{\mathrm{C}:\mathrm{N}}_{\mathrm{Pro}}\)	Y_CN_protein	a_Y_CN_protein	5.3/1.4	molC / molN	C/N molar ratio in protein
\(Y^{\mathrm{N}:\mathrm{C}}_{\mathrm{Chl}}\)	Y_NC_chl	a_Y_NC_chl	4.0/55.0	molN / molC	N/C molar ratio in chlorophyll
\(Y^{\mathrm{C}:\mathrm{N}}_{\mathrm{Nsto}}\)	Y_CN_cyano	a_Y_CN_cyano	2.0	molC / molN	C/N molar ratio of cyanophycin
\(Y^{\mathrm{P}:\mathrm{N}}_{\mathrm{RNA}}\)	Y_PN_nucacid	a_Y_PN_nucacid	1/3.75	molP / molN	P/N molar ratio of RNA
\(Y^{\mathrm{C}:\mathrm{N}}_{\mathrm{DNA}}\)	Y_CN_DNA	a_Y_CN_DNA	9.75/3.75	molC / molN	C/N molar ratio of DNA
\(Y^{\mathrm{C}:\mathrm{N}}_{\mathrm{RNA}}\)	Y_CN_RNA	a_Y_CN_RNA	9.50/3.75	molC / molN	C/N molar ratio of RNA
\(Y^{\mathrm{P}}_{\mathrm{Thy}}\)	Y_THY_P	a_Y_THY_P	0.028163	molP / (molC in Chl)	phosphorus in thylakoid membrane to chlorophyll
\(Y^{\mathrm{Fe}:\mathrm{N}}_{\mathrm{Pho}}\)	Y_FeN_photo	a_Y_FeN_photo	0.00163	molFe / molN	Fe/N ratio in photosystem iron

Table 8.39 Dependent traits of the macromolecular growth model

symbol	trait	units	description
\(Q_{\mathrm{N}}^{\mathrm{Pro\_Other}}\)	QN_pro_other	molN / molC	cellular nitrogen in essential proteins
\(Q_{\mathrm{N,min}}^{\mathrm{RNA}}\)	QN_RNA_min	molN / molC	constant part of RNA in nitrogen
\(Q_{\mathrm{C,min}}^{\mathrm{RNA}}\)	QC_RNA_min	molN / molC	constant part of RNA in carbon
\(Q_{\mathrm{N}}^{\mathrm{DNA}}\)	QN_DNA	molN / molC	DNA in nitrogen
\(Q_{\mathrm{P}}^{\mathrm{DNA}}\)	QP_DNA	molP / molC	DNA in phosphorous
\(A_{\mathrm{Thy}}\)	A_thy	molC / (molC in chl)	ratio of carbon in thylakoid membrane to chlorophyll
\(A^{\mathrm{N}}_{\mathrm{RNA}}\)	AN_RNA	s molN / molN	constant for variable part of RNA
\(V^{\min}_{\mathrm{I}}\)	VI_min	molC/s / (molC in Chl)	minimum photosynthesis rate
\(Q_{\mathrm{C,max}}^{\mathrm{Chl}}\)	QC_chlMax	molC / molC	maximum chlorophyll concentration at minimum light
\(Q_{\mathrm{N}}^{\text{no-Chl}}\)	QnNoChl	molN / molC	minimum QN at zero growth rate
\(Q_{\mathrm{P}}^{\text{no-Chl}}\)	QpNoChl	molP / molC	minimum QP at zero growth rate
\(Q_{\mathrm{Fe}}^{\text{no-Chl}}\)	QfeNoChl	molFe / molC	minimum QFe at zero growth rate
\(Q_{\mathrm{C}}^{\mathrm{const}}\)	QC_const	molC / molC	constant portion of the cell

Table 8.40 Parameters of the macromolecular growth model

param	default	units	description
TempAeArrMacromol	–8420	K	slope for pseudo-Arrhenius for macromolecular (TEMP_VERSION 2)