? Ribosome – Definition and Explanations

Introduction

The ribosomes are ribonucleoprotein complexes (i.e. combinations of proteins and RNA) present in eukaryotic and prokaryotic cells. Their function is to synthesize proteins by deciphering the information contained in messenger RNA. It consists of ribosomal RNAs that carry themactivity (The term activity can refer to a profession.) catalytic and ribosomal proteins. Ribosomes consist of two subunits, a smaller one that “reads” the messenger RNA and a larger one. to fill (Cargo means what it really is…) from synthesis protein (A protein is a biological macromolecule consisting of one or more…) relevant.

Location

They are free in the cytoplasm or associated with the membranes of the endoplasmic reticulum or the envelope. nucleus (The term nuclear energy has two meanings depending on the context 🙂even in some bacteria (Bacteria (Bacteria) are prokaryotic single-celled living organisms, characterized by…) to their membrane internal (In France, this name designates a doctor, pharmacist or dental surgeon…) (for example, Escherichia coli). A chain of ribosomes is called a polysome or polyribosome. Ribosomes are also found in mitochondria and some plastids, which are made up of prokaryotic ribosomes. This is explained by theory (The word theory comes from the Greek word theorein and means “to think, observe,…” from endosymbiosis.

Functions

The ribosome is the “machine” that ensures their translation molecule (A molecule is an electrically neutral chemical compound consisting of at least two atoms, which…) in mRNA protein synthesis (Protein synthesis is the act by which a cell assembles a chain…). the genetic code (The genetic code determines the correspondence system that is activated during . . . ) provides correspondence (Correspondence is usually an exchange of mail extending over a long period of time. The…) between the mRNA sequence and the sequence of the synthesized polypeptide. The ribosome uses transfer RNA, or tRNA, as an “adaptor” between messenger RNA and amino acids.

Messenger RNA passes through a small subunit (30S or 40S) that contains binding sites for tRNAs in mRNA. The large subunit contains the catalytic part that synthesizes the peptide bond between consecutive amino acids of the protein. The large subsection also contains a tunnel (A tunnel is an underground gallery providing access to a means of communication (…) through chain (The string of words can have several meanings 🙂 protein is synthesized. The large subunit contains three sites (the A or Aminoacyl site, the P or Peptidyl site, and the E or Exit Site) where tRNAs carrying amino acids will bind during translation. Site (P) is occupied by a tRNA carrying a amino acid (An amino acid is an organic molecule with a carbon skeleton and…) binds to the resulting polypeptide chain. Site (A) is in turn occupied by tRNA carrying a acid (An acid is a chemical compound generally defined by its reactions…) the amine is waiting to be attached to the polypeptide chain. Finally, site (E) allows the release of the deacetylated tRNA that delivers the amino acid.

The ribosome is also a engine (An engine (Latin mōtor: “that moves”) is a device…) moves forward on the molecular, consuming messenger RNAenergy (Energy in common sense refers to anything that allows you to do work, energize, etc.) It is provided by the hydrolysis of GTP. Several proteins, called elongation factors, are involved in this action, called translocation.

They also have a reducing function in Ca proton pumps²⁺/K⁺

Structure

Atomic structure of the 50S large subunit of the ribosome.
Proteins are stained blue (Blue (from Old High German “blao” = bright) is one of the three colors…) and RNAs in orange. active site,adenine (Adenine is an essential compound for life. We find this molecule everywhere…) It has 2486 colors red (Red meets different definitions depending on the chromatic system we use…).

Composed of RNA and ribosomal proteins called ribosomal RNA (or rRNA), they consist of two subunits: a large (L for L) wide) and small (for S small) subunit. These subsections are established around (Autour is the name given by French bird nomenclature (update)…) ribosomal RNA core with a very compact structure to which proteins are attached. which is the active site of the ribosome catalysis (Catalysis is the action of a substance called a catalyst on a chemical transformation…) peptide bond consists of RNA. The biogenesis of ribosomes takes place in the nucleus, which is a structure of the nucleus.

• Large subunit: In the cytoplasmic ribosome of eukaryotes, it consists of three rRNA molecules (5S, 28S, and 5.8S of one hundred twenty, four thousand seven hundred, and one hundred sixty nucleotides, respectively) and 49 ribosomal proteins. This is a great subsection mass (The term mass is used to define two quantities related to one another…) molecular weight 2.8.10⁶ Daltons, a coefficient (In mathematics, a coefficient is a multiplicative factor that depends on a certain…) 60S sediment. In prokaryotes, this large subunit is characterized by the 50S sedimentation coefficient; It consists of 23S RNA (2300 nucleotides), 5S RNA (120 nucleotides) and thirty-four proteins.
• Small subunit: In the cytoplasmic ribosome of eukaryotes, it consists of only one rRNA molecule (18S of nineteen hundred nucleotides) and thirty-three ribosomal proteins. The molecular mass of this minor subunit is 1.4.10⁶ Daltons, sedimentation coefficient 40S. In prokaryotes, it consists of 16S rRNA (1540 nucleotides) and twenty one proteins. Its sedimentation coefficient is 30S.

Horse common (Total is an absolute quality without exception. In accounting terms, a…)a functional ribosome (consisting of two subunits that join each other) has a molecular weight of 4.2.10⁶ Daltons, the sedimentation coefficient of 80S in eukaryotes and 70S in prokaryotes.

The 70S ribosomes of prokaryotes are sensitive to certain antibiotics, unlike the 80S ribosomes of eukaryotes.

In addition to having their own DNA and reproductive machinery, mitochondria and chloroplasts (plant cells) also contain 70S ribosomes. thesis (Thesis (translated from Greek thesis, “the act of posing”) …) therefore, these organelles come from prokaryotes symbiosis (Symbiosis is an intimate and continuous association between two organisms…) with a eukaryotic cell (endosymbiosis theory).