What is lumen in plastids?

Lumen:

1. The stroma is the name for the lumen in the chloroplast.
2. The whitish fluid that surrounds the grana (stacks of thylakoids) within the chloroplast is referred to as the stroma.
3. The thylakoid membrane surrounding space is called a lumen.
4. The photosystems located in the thylakoid membranes capture light energy.
5. Plant plastids are the biggest cell organelle.
6. These are involved in photosynthesis, operate as starch storage devices, and aid in the creation of different compounds like fatty acids and terpenes.