What is missing in animal cells

Endoplasmic reticulum: The endoplasmic reticulum (ER) is characterized by a strongly labyrinthine duct system. A basic distinction is made between rough and smooth endoplasmic reticulum. The smooth ER functions primarily as a storage location for calcium ions, whereas the rough ER is where translation (protein biosynthesis) takes place in the animal cell.

scourge: Cell processes for locomotion are called flagella. Flagella are more typical of bacteria (prokaryotes), but can also be found in eukaryotes.

Golgi apparat: The Golgi apparatus (called dictyosomes) consists of a cyst-like system with flat cavities and close proximity to the cell nucleus. In the Golgi apparatus, protein biosynthesis is accelerated by attaching additional proteins to the amino acid chains synthesized by the ribosome.

Nuclear corpuscles: The nuclear corpuscles (lat. Nucleolus) are small corpuscles consisting of RNA (ribonucleic acid) which are located in the cell nucleus and play a decisive role in the initiation of the transcription of ribosobal RNA. Nuclear bodies are in no way to be equated with the cell nucleus (lat. Nucleus)!

Lysosomes: Lysosomes are small vesicles produced by the Golgi apparatus that can digest cell waste. Endocytosis traps the waste in the round lysosomes and special digestive enzymes break it down into its basic components so that the cell can use them again to build new molecules.

Microtubules: The microtubules, together with the actin and intermediate filaments, form the cytoskeleton of the animal cell. In contrast to plant cells, the stability of which is largely determined by cell walls, in animal cells the interaction of the protein-rich filaments ensures a stable, yet flexible network.

Mitochondria: In the mitochondria, the citric acid cycle and the respiratory chain, two elementary processes take place that are responsible for the supply of energy within the animal cell. This is why mitochondria are also known as the "power plants of the cells". By the way: The proportion of mitochondria in the cells is much higher in cells with above-average energy consumption (e.g. muscle cells) than in cells with lower energy consumption.

Peroxisomes: The structure of the circular peroxisomes (microbodies) is similar to that of normal transport vesicles. However, their primary task is to actively detoxify the cell. To do this, they reduce hydrogen peroxide via enzymatic reactions (peroxidase) into harmless water.

Ribosomes: The translation takes place on the ribosomes, i.e. the translation of the genetic code into amino acid chains. Ribosomes largely consist of RNA (ribonucleic acid) and proteins. The number of ribosomes is around 100,000 units per cell and is distributed between the cytoplasm, the rough endoplasmic reticulum and the mitochondria.

Secretory vesicle: So that the animal cell can drain waste and toxins from the inside, these substances have to penetrate the cell membrane. Secretory vesicles (or Golgi vesicles) fuse with the membrane (exocytosis) and release the contents of the vesicles to the outside.

Cell nucleus: The spherical cell nucleus (nucleus) contains the genetic material (in the form of chromosomes, which for the most part consist of deoxyribonucleic acid) of the animal cell. Two important processes take place in the cell nucleus: DNA replication and transcription.

Cell membrane: The cell membrane, consisting of a lipid bilayer, completely envelops the animal cell and, thanks to its semi-permeable property (only permeable to certain substances), maintains the cell's internal balance (homeostasis) by regulating the inflow and outflow of particles.

Centrosome: In the immediate vicinity of the cell nucleus, each animal cell has exactly one centrosome, which consists of two centrioles. In the course of mitosis and meiosis, the centrioles form the spindle apparatus that is responsible for separating the chromosomes through their pulling action.

cytoplasm: The cytoplasm is the totality of the cell content, consisting of the cytosol (fluid in the cell), the cytoskeleton (proteins with a supporting function) and the cell organelles (mitochondria, cell nucleus, lysosomes, etc.). With a share of approx. 4/5, water is the main component, the cytoplasm.