Provide definitions/explanations for the following terms:
$(1)$ Dark reaction
$(2)$ Photophosphorylation

(N/A) $(1)$ The dark reaction,also known as the biosynthetic phase of photosynthesis,is the process that utilizes the products of the light reaction ($ATP$ and $NADPH$) to fix $CO_2$ into carbohydrates. It does not directly require light,but it is dependent on the products of the light-dependent reactions.
$(2)$ Photophosphorylation is the process in which $ADP$ combines with inorganic phosphate $(Pi)$ to form $ATP$ using the energy derived from light (photons) during the light-dependent reactions of photosynthesis.