Development of Analytical and Preparatory Techniques - Chlorophyll Biosynthesis and Technological Applications - page 123

Fig. 3.1 The three possible
irreversible
precursor-product
relationships between two
precursors,P,A,andone
end product, B (Adapted
from Rebeiz et al. 1988 )

If compound B is formed exclusively from A, the increase in B during a small
time interval dt is given by

d B ¼ a : d t : (3.87)

Furthermore, since it is assumed that compound B is formed exclusively from A,
the radioactivity d qb that accumulates in compound B during time dt is given by

dq B ¼ Y A dB (3.88)

where Y A is the specific radioactivity of compound A during the small time interval
dt, and dB is the increase in B during time interval d t .
By substituting Eq. ( 3.87 ) for d B in Eq. ( 3.88 ), the latter transforms into

d q B ¼ð Y A Þ a : dt : (3.89)