What is cytomplasm


from Greek: kýtos - "vessel", "cavity" and plásma - "structure"
Synonym: cytoplasm
English: cytoplasm

1 definition

The cytoplasm is the entire living content of a cell, which is enclosed by the cell membrane on the outside. In plant cells, which have a huge central vacuole inside, the cytoplasm is separated from the plasmalemma on the outside and on the inside - against the vacuole - by the tonoplast, another biomembrane.

2 rough composition

The cytoplasm itself consists of:

In prokaryotes (e.g. bacteria) the genetic material lies freely in the cytoplasm in the form of DNA, in eukaryotes it lies in the cell nucleus.

3 compartments

There are topographically different compartments of the cytoplasm:

4 Chemical composition

From a chemical point of view, the cytoplasm consists of numerous organic, but also inorganic substances. With 80 to 85% water content, the water content is high. The following list shows the average composition of animal cells:

  • Water 80.5–85%
  • Proteins 10-15%
  • Lipids 2-4%
  • Polysaccharides 0.1-1.5%
  • DNA 0.4%
  • RNA 0.7%
  • small organic molecules 0.4%
  • inorganic molecules and ions 1.5%

The pH value of the cytoplasm is usually around 7. However, since protons are often bound or released during metabolic reactions, the cytoplasm is buffered. The pH value can also be changed or stabilized by means of ion pumps.

The cytoskeleton, which is dynamically built up and broken down, is located in the cytoplasm. This stabilizes the cell, provides solid pathways for vesicle transport and causes intracellular movements such as cytoplasmic flow, organelle and chromosome transport. The cytoplasmic flow only takes place in the endoplasm, it contributes to the mixing.

see also:Nucleoplasm, proteasome