38
system. For given values of AI' A 4 , q12' q34' z12' and z34' there is
-1
an optimum value for A 2 .
If A2 decreases below +28 kcal· (mole e)
the overall efficiency of energy conversion, n 14 , drops below its maximum value of 0.23. This decrease is caused mostly by a rapid decrease
in the efficiency ~t coupling site 1-2. On the other hand, if A2 increases above a value of +28, the overall efficiency of energy conversion drops because of a rapid decrease in the efficiency at coupling
site 3-4.
III. PREDICTIONS FOR LIGHT LIMITED GROWTH
Since Al and A4 are known constants and J i is an input into the
model, the 12 equations (3-14) contain 13 unknowns.
An additional relationship, lSa, describes the chlorophyll content of the phytoplankton
cells as a function of incident light intensity.
ChI = 6.0 x 10- 4 - 1.8 x 10-2' Ji
when J. < 1.9 x 10-2m ein'cm- 2 'hr- l
J. -
(lSa)
This empirical relationship is based upon measurements of the lightlimited continuous culture of Chlorella pyrenoidosa by Myers and Graham
(1971); the observed linear relationship between cellular chlorophyll
and light intensity is limited to intensities that are subsaturating to
growth.
, .
• r ~
,
1·
.. ,
! •
,
i .
Figure 2. Responses to I ight levels
predicted by the thermodynamic model.
This figure shows variations in specific
growth rate, ~, cellular chlorophyll,
ChI, catalytic capacity at the 2 coupling
sites, ll2 and l34, quantum efficiency,
¢, and the chemical affinity of reaction
2, A 2 , with variations in i rradiance.
(The solution of equations 3-lSa at subsaturating light levels are presented in Figure 2.)
According to the model, the cells maintain a constant quantum efficiency of photosynthesis, ¢ = JC02/J4' and a constant driving potential
for photosynthetic electron transport despite changes in growth rate
and cellular chlorophyll. Changes in the cross coefficients, L12 and
L34 of the phenomenological equations parallel changes in growth rate.
As discussed previously, these conductivity terms index the enzymatic
system. For given values of AI' A 4 , q12' q34' z12' and z34' there is
-1
an optimum value for A 2 .
If A2 decreases below +28 kcal· (mole e)
the overall efficiency of energy conversion, n 14 , drops below its maximum value of 0.23. This decrease is caused mostly by a rapid decrease
in the efficiency ~t coupling site 1-2. On the other hand, if A2 increases above a value of +28, the overall efficiency of energy conversion drops because of a rapid decrease in the efficiency at coupling
site 3-4.
III. PREDICTIONS FOR LIGHT LIMITED GROWTH
Since Al and A4 are known constants and J i is an input into the
model, the 12 equations (3-14) contain 13 unknowns.
An additional relationship, lSa, describes the chlorophyll content of the phytoplankton
cells as a function of incident light intensity.
ChI = 6.0 x 10- 4 - 1.8 x 10-2' Ji
when J. < 1.9 x 10-2m ein'cm- 2 'hr- l
J. -
(lSa)
This empirical relationship is based upon measurements of the lightlimited continuous culture of Chlorella pyrenoidosa by Myers and Graham
(1971); the observed linear relationship between cellular chlorophyll
and light intensity is limited to intensities that are subsaturating to
growth.
, .
• r ~
,
1·
.. ,
! •
,
i .
Figure 2. Responses to I ight levels
predicted by the thermodynamic model.
This figure shows variations in specific
growth rate, ~, cellular chlorophyll,
ChI, catalytic capacity at the 2 coupling
sites, ll2 and l34, quantum efficiency,
¢, and the chemical affinity of reaction
2, A 2 , with variations in i rradiance.
(The solution of equations 3-lSa at subsaturating light levels are presented in Figure 2.)
According to the model, the cells maintain a constant quantum efficiency of photosynthesis, ¢ = JC02/J4' and a constant driving potential
for photosynthetic electron transport despite changes in growth rate
and cellular chlorophyll. Changes in the cross coefficients, L12 and
L34 of the phenomenological equations parallel changes in growth rate.
As discussed previously, these conductivity terms index the enzymatic