Suppose that, for every two photons of light striking photosystem II (see the Light Reactions tutorial), one ATP molecule is produced at ATP synthase. The ATP then goes to the Calvin cycle and participates in PGAL synthesis; two PGALs combine to form one glucose molecule. Considering the assumptions above, how many photons of light must strike photosystem II to generate the ATP necessary to produce one glucose molecule in the Calvin cycle?

When does a spring tide occur? question 9 options: they occur when the sun, moon, and earth are aligned. in spite of their name, these tides occur twice a year in the spring and fall. they occur on the date of the vernal equinox each year, no matter what stage the moon is in. this is why they are called spring tides. they occur when the sun, moon, and earth are at 45-degree angles from each other. this happens once every spring. they occur when the sun, moon, and earth are aligned. in spite of their name, these tides occur all year long.