AP BIOLOGY

Detailed explanation-1: -Within the chloroplast is a third membrane that forms stacked, disc-shaped structures called thylakoids. Embedded in the thylakoid membrane are molecules of chlorophyll, a pigment (a molecule that absorbs light) through which the entire process of photosynthesis begins.

Detailed explanation-2: -Chloroplast thylakoids frequently form stacks of disks referred to as grana (singular: granum). Grana are connected by intergranal/stromal thylakoids, which join granum stacks together as a single functional compartment.

Detailed explanation-3: -The thylakoid membrane contains a series of embedded pigments and proteins that are essential to perform the light-dependent reactions of photosynthesis. In order, these are Photosystem II, plastoquinone, cytochrome b6f, plastocyanin, Photosystem I, ferredoxin, and NADP+ reductase.

Detailed explanation-4: -hollow disks that are called thylakoids (“saclike”). The chloroplasts of most higher plants have regions, called grana, in which the thylakoids are very tightly stacked.