Experimental evidence for the Calvin Cycle (cyclic photophosphorylation)

A resource aimed at advanced level biology students, this worksheet leads students through an area that often causes difficulty - interpreting evidence for the Calvin Cycle. The worksheet looks at the classic experiment performed by Melvin Calvin that provided evidence for the sequence of events that occurs in cyclic photophosphorlyation or the light-independent reactions of photosynthesis. The worksheet introduces the idea of radioactive tracers and asks students to predict the effect of switching lights off or reducing carbon dioxide levels. Graphs are shown recording the levels of RuBP and GP in response to these changes.

Answers to each question are provided on the second page of this worksheet

Key words: Light independent reaction, cyclic photophosphorylation, ATP, RNADP, glycerate - 3- phosphate, triose phosphate, ribulose bisphosphate, ribulose phosphate, light dependent reaction, calvin cycle