Which components are absent in the stroma lamellae? 

The stroma lamellae membranes lack PS II as well as NADP reductase enzyme. Since only PS I is functional, the electron is circulated within the photosystem and the phosphorylation occurs due to cyclic flow of electrons.

The cyclic flow hence, results only in the synthesis of ATP, but not of NADPH + H+ . Cyclic photophosphorylation also occurs when only light of wavelengths beyond 680 nm are available for excitation.