A seaport is a major facility in a city, for the loading, unloading, and movement of cargo; to and from from oceanicships. The term also refers to a city with such a facility. (See also: port)
... two different pathways, cyclic or non-cyclic.
Cyclic photophosphorylation
In cyclic electron flow, the electron originates in a pigment complex called photosystem I, ...