Search results
Results from the WOW.Com Content Network
The cell nucleus (from Latin nucleus or nuculeus 'kernel, seed'; pl.: nuclei) is a membrane-bound organelle found in eukaryotic cells.Eukaryotic cells usually have a single nucleus, but a few cell types, such as mammalian red blood cells, have no nuclei, and a few others including osteoclasts have many.
The cytoplasm describes all the material within a eukaryotic or prokaryotic cell, enclosed by the cell membrane, including the organelles [1] and excluding the nucleus in eukaryotic cells. The material inside the nucleus of a eukaryotic cell and contained within the nuclear membrane is termed the nucleoplasm .
Some protein complexes contain a large central cavity that is isolated from the remainder of the cytosol. One example of such an enclosed compartment is the proteasome. [48] Here, a set of subunits form a hollow barrel containing proteases that degrade cytosolic proteins.
The nucleus is spherical and separated from the cytoplasm by a double membrane called the nuclear envelope, space between these two membrane is called perinuclear space. The nuclear envelope isolates and protects a cell's DNA from various molecules that could accidentally damage its structure or interfere with its processing.
As red blood cells contain no nucleus, protein biosynthesis is currently assumed to be absent in these cells. Because of the lack of nuclei and organelles, mature red blood cells do not contain DNA and cannot synthesize any RNA (although it does contain RNAs), [57] [58] and consequently cannot divide and have limited repair capabilities. [59]
Nucleoplasm is quite similar to the cytoplasm, with the main difference being that nucleoplasm is found inside the nucleus while the cytoplasm is located inside the cell, outside of the nucleus. Their ionic compositions are nearly identical due to the ion pumps and permeability of the nuclear envelope, however, the proteins in these two fluids ...
Nucleoli of various plant species have been shown to have very high concentrations of iron [16] in contrast to human and animal cell nucleoli. The nucleolus ultrastructure can be seen through an electron microscope, while the organization and dynamics can be studied through fluorescent protein tagging and fluorescent recovery after ...
White fat cells contain a single large lipid droplet surrounded by a layer of cytoplasm, and are known as unilocular. The nucleus is flattened and pushed to the periphery. A typical fat cell is 0.1 um in diameter [2] with some being twice that size, and others half that size.