Suppose you discovered a mutant strain of spinach in which the thylakoid membranes were slightly permeable to protons, thus allowing a slow leakage. (remember that normal membranes are not permeable to protons at all.) how might this defect affect the yield of atp or nadph from the light reactions

ATP yield would decrease

Explanation:

In plant Carbon dioxide enters through Stomata and in stomata it diffuses over short distances through the intercellular process. it reaches the mesophyll cells. The other name of light independent phase is Calvin cycle whose name is in name of the person who discovered it. The light is not involved in this reaction so it is called light independent or dark cycle.  

it would be heredity