Question

Ribosomes are the centre for
A. Respiration
B. Photosynthesis
C. Protein synthesis
D. Fat synthesis

Answer 1

Hint: Ribosome is a cell organelle which is present in large numbers in living cells. It occurs both as free particles in prokaryotic and eukaryotic cells and as particles attached to the membranes of the ER in eukaryotic cells.

Complete answer:
Ribosomes are organelles composed of riboproteins and ribonucleoproteins. Each complete ribosome is built from two sub-units. Ribosomes are found in prokaryotic and eukaryotic cells; in mitochondria, chloroplasts and bacteria. Those found in prokaryotes are smaller than those in eukaryotes. The proteins and nucleic acids that form the ribosomal subunits are made within the nucleolus and exported through nuclear pores into the cytoplasm.
After they have synthesized a polypeptide the 2 subunits separate and are either re-used or shifting.

Structure:

Around 37 to 62% of RNA is composed of RNA and also the rest is proteins.
Each ribosome is split into two subunits:
A smaller subunit which binds to a bigger subunit and also the mRNA pattern, and
A larger subunit which binds to the tRNA, the amino acids, and also the smaller subunit.

Functions:

• The ribosome can be defined as a complex molecular machine, found within all living cells, that is the positioning of biological protein synthesis (translation).
• Ribosomes link amino acids together within the order specified by informational RNA (mRNA) molecules.
• Ribosomes act as catalysts in two extremely important biological processes called peptidyl transfer and peptidyl hydrolysis.
• Translate encoded information from the cell organ provided by messenger polymer (mRNA)
• Link together amino acids selected and picked up from the cytoplasm by transfer polymer (tRNA).
• Ribosomal molecules of mRNA determine the order of RNA (tRNA) molecules that are certain to nucleotide triplets (codons).
• Ribosomes are the sites at which information carried within the ordering is converted into protein molecules.
• Molecules of rRNA catalyze the peptidyl transferase reaction, which forms peptide bonds between the amino acids, linking them together to create proteins. The newly formed proteins detach themselves from the ribosome site and migrate to other parts of the cell to be used.
• Export the polypeptide produced to the cytoplasm where it'll form a functional protein.

Therefore, the correct answer is C, protein synthesis.

Note: In eukaryotes, ribosomes get their orders for protein synthesis from the nucleus, where portions of DNA (genes) are transcribed to create messenger RNAs (mRNAs). An mRNA travels to the ribosome, which uses the data it contains to make a protein with a selected amino alkanoic acid sequence. This process is termed translation. Prokaryotes lack a nucleus, so their mRNAs are transcribed within the cytoplasm and might be translated by ribosomes immediately. Eukaryotic ribosomes could also be either free, meaning that they're floating around within the cytoplasm, or bound, meaning that they're attached to the endoplasmic reticulum or the surface of the nuclear envelope.