Chromoplasm:
The word Chromoplasm has different meanings in genetics and bacterial cell biology.
In genetics:
- The matrix in which the nucleolus is suspended along with other nuclear proteins that remains bound by the nuclear membrane is called the nucleoplasm.
- Chromoplasm is referred to the part of the nucleoplasm that condenses to form the chromosomes.
- It is rich in chromatin threads (that contain DNA) and histone proteins.
In bacterial cell biology:
- It is defined as the material present in the periphery of the cytoplasm in cyanobacteria (blue-green bacteria).
- It is rich in thylakoids and hence contains the pigment chlorophyll.
- In addition to chlorophyll-containing thylakoids, chromoplasm is also rich in the pigments that impart the blue (phycocyanin) and red (phycoerythrin) pigments.
- It also contains stored lipids and carbohydrate molecules.