Protein Synthesis And Ribosomes Role In The Cytoplasm
The cytoplasm describe the contents of a living cell. More precisely, it is the entire cellular material of protoplasm bounded by the plasma membrane .It is a colloidal emulsion composed of grainy or hyaloplasm cytosol. In eukaryotes, the cytoplasm contains many organelles such as ribosomes, the reticulum, vacuoles, mitochondria and chloroplasts, but does not include the kernel (the content is called nucleoplasm). In prokaryotes, the cytoplasm encompasses the entire cellular material contained in the inner membrane (or cytoplasmic). It contains no organelles but ribosomes, reserve substances, plasmids and a circular chromosome.
The cytoplasm can divide and form outside the cell a gelatinous mass, called ectoplasm, which contributes to cell movement. It can then present within an area more fluid, called endoplasm, which is where most of the organelles. The cytoplasm is a medium rich in nutrients that pass through the plasma membrane and migrate to organelles.
In eukaryotes, the cytoplasm consists of a more or less homogeneous, cytosol, that surrounds organelles. The cytoplasm consists of a network of membranes known as the endoplasmic reticulum (smooth and rough) that serve as a work surface for all biochemical activities. It contains a small portion of the genome of an organism. Although most of the genome is contained in the cell nucleus, some organelles in the cytoplasm, mitochondria and chloroplasts (in plants), have their own DNA . This cytoplasmic genome is transmitted mostly through mother (that is to say by the female gamete).
The cytoplasm consists of a network of protein filaments that gives the cell its shape and internal organization and allows it to move . These filaments form the cytoskeleton. It may still encounter several types of filaments:
-Actin filaments or microfilaments typical of muscle cells,
-Microtubules, which appear scattered in the hyaloplasm or form more complex structures, such as time achromatic
- Intermediate filaments such as keratin filaments typical of epidermal cells.
In turn, this structure maintains a link between protein structures and generates more complex and more stable. They are also responsible for movement cytology.
Ribosomes are cytoplasmic granules present in all cells, measuring about twenty nanometers. Moreover, they carry the ribosomal RNA.
Protein synthesis takes place in these ribosomes in the cytoplasm . Messenger RNA (mRNA) and transfer RNAs (tRNAs) are synthesized in the cell nucleus before being released into the cytoplasm. The ribosomal RNA (rRNA) is released into the cytoplasm in the form of a ribosomal subunit. Two types of such subunits can then be combined with mRNA molecules to form an active ribosome .
Active ribosomes can then either remain suspended in the cytoplasm, is set on the rough endoplasmic reticulum . Those that remain suspended main function of protein synthesis following:
1. proteins that form the cytosol
2. proteins that build the structural elements
3. proteins that make up the moving parts of the cytoplasm
The ribosome consists of two parts, a minor subunit and a subunit of major emerging each kernel . Experiments have shown that they are held together with loads, because when we lowered the concentration of Mg +2, sub-units tend to separate.
Lysosomes are spherical vesicles with diameters ranging between 0.1 and 1 micron. They contain nearly fifty enzymes, mostly hydrolyzed in acidic solution. The enzymes have indeed need this acid solution for optimal operation. Lysosomes can maintain these enzymes away from the rest of the cell because, otherwise, they may react chemically with the elements and organelles thereof.
They use their enzymes to recycle the different organelles of the cell by absorbing them, assimilating them and then releasing its components within the cytosol. This process is known as autophagy, a process in which the cell digests its own structures become unnecessary. These structures are encompassed by vesicles derived from endoplasmic reticulum and Golgi apparatus, forming an autophagosome. If it joins a primary lysosome, they then form a autophagolysosome and follows the same process as presented above.
During endocytosis, the materials are gathered outside the cell and covered by the plasma membrane to form a phagosome. Unites with the lysosome phagosome to form a phagolysosome and then emptied into the lysosome after being degraded. Once hydrolysed, the useful molecules are released inside the cell to reach the metabolic pathways. The rest is removed by exocytosis.
Lysosomes also discharge their enzymes into the external environment by exocytosis to degrade also other structures.Given their role, we found lot inside white blood cells because they allow the degradation of foreign material.
About the Author:
Anna Kerry is the author of comunicacionmanual.org . comunicacionmanual is a leader in the business of ecommerce Websites, Ecommerce Templates. comunicacionmanual mission is to help people getting good opportunities. Learn more about Ecommerce Solutions at comunicacionmanual related site.
Article Marketing
3 people like this article
