photorespiration

As a noun photorespiration

is (biology) the light-dependent release of carbon dioxide and uptake of oxygen in photosynthetic organisms; an unavoidable side reaction of photosynthesis.

As a proper noun calvin is

a surname of french and spanish origin, meaning a bald person.

Phootosynthesis is likely misspelled.

Phootosynthesis has no English definition.

As a noun photorespiration is

the light-dependent release of carbon dioxide and uptake of oxygen in photosynthetic organisms; an unavoidable side reaction of photosynthesis.