Explain the structure of the chloroplast.

(N/A) The chloroplast is a double-membrane-bound organelle. Its structure consists of the following components:
$1$. Membrane System: It consists of grana,stroma lamellae,and the fluid stroma. The membrane system is responsible for trapping light energy and for the synthesis of $ATP$ and $NADPH$.
$2$. Stroma: The stroma is the fluid-filled matrix where enzymatic reactions occur. These reactions incorporate $CO_{2}$ into the plant,leading to the synthesis of sugar,which is subsequently stored as starch.
$3$. Functional Division: There is a clear division of labour within the chloroplast.
- Light Reactions: The reactions occurring in the membrane system are directly light-driven and are called light reactions.
- Dark Reactions: The reactions occurring in the stroma are not directly light-driven but depend on the products of light reactions ($ATP$ and $NADPH$). By convention,these are called dark reactions,though this does not mean they occur in darkness or are independent of light.