AP BIOLOGY

Detailed explanation-1: -Stroma is the fluid filling up the inner space of the chloroplasts which encircle the grana and the thylakoids. In addition to providing support to the pigment thylakoids, the stroma are now known to contain chloroplast DNA, starch and ribosomes along with enzymes needed for Calvin cycle.

Detailed explanation-2: -The green pigment chlorophyll is located within the thylakoid membrane, and the space between the thylakoid and the chloroplast membranes is called the stroma (Figure 3, Figure 4).

Detailed explanation-3: -In thylakoid membranes, chlorophyll pigments are found in packets called quantasomes. Each quantasome contains 230 to 250 chlorophyll molecules.

Detailed explanation-4: -Each stack of thylakoids is called a granum (plural = grana). The fluid enclosed by the inner membrane and surrounding the grana is called the stroma. Figure 2 This simplified diagram of a chloroplast shows the outer membrane, inner membrane, thylakoids, grana, and stroma.