What is a Polysome and what is its function?
A polyribosome (or polysome or ergasome) is a group of ribosomes bound to an mRNA molecule like “beads” on a “thread”. It consists of a complex of an mRNA molecule and two or more ribosomes that act to translate mRNA instructions into polypeptides.
What do Polysomes do?
Polysomes are aggregates of numerous ribosomes that are in the process of actively translating mRNA into protein. By light microscopy polysomes appear as basophilic cytoplasmic granules, but are extremely labile during postmortem change in the liver.
What is Polysome Class 11?
The polysome is a structure formed when several ribosomes attach to a single-stranded mRNA to form a chain.
What is a Polyribosome in biology?
: a cluster of ribosomes linked together by a molecule of messenger RNA and forming the site of protein synthesis.
Where is Polysome found?
Polysomes are found either free in the cytoplasm or attached to the surface of membranes of the endoplasmic reticulum (ER) and the nucleus.
What is the advantage of Polyribosomes?
What are the advantages of polyribosomes? This occurs when multiple ribosomes translate a single mRNA simultaneously- forms polyribosome / polysome. Polyribosomes allow many polypeptides to be synthesized simultaneously, which makes the process more efficient.
Is tRNA a ribosome?
Transfer ribonucleic acid ( tRNA ) is a type of RNA molecule that helps decode a messenger RNA (mRNA) sequence into a protein. tRNAs function at specific sites in the ribosome during translation, which is a process that synthesizes a protein from an mRNA molecule.
Why does the code have to be in triplets?
The code has to be in triplets because there are only 4 bases of DNA which must code for the 20 amino acids. Triplets are the smallest unit of uniform length that can code for all amino acids. Nirenberg synthesized mRNA with identical letters to determine the codons for four amino acids.
What sequence of processes is carried out during translation?
Translation of an mRNA molecule by the ribosome occurs in three stages: initiation, elongation, and termination. During initiation, the small ribosomal subunit binds to the start of the mRNA sequence.
What is the function of Polysome Class 11?
Answer. Answer: A polyribosome (or polysome or ergasome) is a group of ribosomes bound to an mRNA molecule like “beads” on a “thread”.  It consists of a complex of an mRNA molecule and two or more ribosomes that act to translate mRNA instructions into polypeptides.
What is a Polysome quizlet?
Polysome. A group of 2 or more ribosomes translating an mRNA sequence simultaneously.
What does S refer in a 70s and 80s ribosome?
Solution: S’ refers to Svedbergs unit for sedimentation coefficient. Sedimentation coefficient depicts that how fast a cell organelle sediments during the ultracentrifugation, In cells heavier the structure, higher is the sedimentation coefficient.
Where are Polyribosomes found?
Polyribosomes are found prokaryotes and eukaryotes both either free in the cytoplasm or can attach to the endoplasmic reticulum (ER) and the nucleus membranes. They are attached to rough endoplasmic reticulum surface and the outer membrane of the nucleus in eukaryotes.
Where does translation occur in biology?
Where Translation Occurs. Within all cells, the translation machinery resides within a specialized organelle called the ribosome. In eukaryotes, mature mRNA molecules must leave the nucleus and travel to the cytoplasm, where the ribosomes are located.
Do Polyribosomes occur in eukaryotes?
In eukaryotes, polyribosomes are attached to the surface of the rough endoplasmic reticulum and the outer membrane of the nucleus; in bacteria they are found free in the cytoplasm.