Acid rain has a greater effect on lakes without limestone because limestone is

The presence of limestone and other calcium carbonate rock in lakes and streams helps to maintain a constant pH because the minerals react with the excess acid. However, acid rain eventually can overcome the buffering capacity of the surface water.

Explanation:

Energy in _SUNLIGHT__ is absorbed by an electron in a photocenter. This energy is converted from light energy into chemical energy into kinetic energy as the energized electron is used in back to back REDOX reaction in the electron transport chain, ETC. The ETC creates _AN ENERGY GRADIENT__ which is used by the cell to power the formation of ATP. In _CYCLIC PHOSPHORYLATION__ (cyclic or noncylcic) the electron returns to the photocenter. In _NON-CYCLIC PHOSPHORYLATION__ (cyclic or non-cyclic), the electron reduces NADP+ to form _NADPH__.

Photophosporylation is the process of using light (photo) to produce ATP from ADP (phosphorylation i.e. addition of phosphorous). There are two types: cyclic and non-cyclic phosphorylation.

In non-cyclic phosphorylation, there are two photosystems (photocenter) involved, and electron is passed to NADP+.

In cyclic phosphorylation,  one photosystem is involved and the electron is not transferred to NADP+, it is circled back to the photosytem.

The reduced form of NADP+ is NADPH. (Remember that: reduction is defined as the addition of hydrogen)