Cell nucleus
The nucleus is the largest cellular organelle in animal cells.
In mammalian cells, the average diameter of the nucleus is approximately 6 micrometres (µm), which occupies about 10% of the total cell volume. The viscous liquid within it is called nucleoplasm (or karyolymph), and is similar in composition to the cytosol found outside the nucleus. It appears as a dense, roughly spherical or irregular organelle. The composition by dry weight of the nucleus is approximately: DNA 9%, RNA 1%, Histone Protein 11%, Residual Protein 14%, Acidic Proteins 65%.
Endoplasm
The term granule refers to a small particle within the endoplasm, typically the secretory vesicles. The granule is the defining characteristic of the endoplasm, as they are typically not present within the ectoplasm. These offshoots of the endomembrane system are enclosed by a phospholipid bilayer and can fuse with other organelles as well as the plasma membrane. Their membrane is only semipermeable and allows them to house substances that could be harmful to the cell if they were allowed to flow freely within the cytosol. These granules give the cell a large amount of regulation and control over the wide variety of metabolic activities that take place within the endoplasm. There are many different types, characterized by the substance that the vesicle contains. These granules/vesicles can contain enzymes, neurotransmitters, hormones, and waste. Typically the contents are destined for another cell/tissue. These vesicles act as a form of storage and release their contents when needed, often prompted by a signaling pathway. Once signaled to move, the vesicles can travel along aspects of the cytoskeleton via motor proteins to reach their final destination.