Photosynthesis dominates the metabolism of green plant cells. Therefore it is not surprising that many other plant activities, such as the opening of stomata or the activity of Photosystem II, are synchronized with the rhythm of photosynthesis. Because these rhythms are synchronized, however, it can be difficult to separate factors that are controlling the photosynthetic rhythm from those that are merely synchronized with it. Scientists learn more about the circadian rhythms of photosynthesis by manipulating organisms and their environment, then measuring the corresponding changes in rhythm. Because circadian rhythms are repeating patterns, we can use principles of trigonometry to quantify them.
Circadian rhythms produce repeating patterns over time.
We can quantify properties of waves such as the amplitude and period. The amplitude of a wave is the height from peak to crest. The period of a wave is the time for completion of one cycle. Circadian rhythms are somewhat more complicated than the simplest sine wave. Instead of 2 p , the period is 24 hours.