Question

What are protoproteins?

Answer 1

Hint: Protoproteins- as the name suggests, are primitive forms of what we call protein today. It is believed that the modern proteins have an evolutionary origin to the protein-like substances.

 Complete answer: It is hypothesized that the substance we call proteins today has evolved from the protoproteins. Protoproteins are nothing but tiny 15-20 residue peptide chains with few elements with a secondary structure.
It has a primitive function.
The present-day stable and functional proteins have evolved by the addition of some structural elements in order to produce small protein modules that we recognize today.
Sometimes a proteinoid is also called a photoprotein.
It is basically a protein-like substance. Proteinoid consists of either a single polypeptide or a mixture of polypeptides. Polypeptides are formed by the polymerization of amino acids.
This reaction occurs under inorganic conditions e.g. temperature over.
These substances were also considered to be the precursors of the first living cell.
This is why it is also known as protrotein.

Note: Protein synthesis occurs by translation. It takes place in a cell-organelle which is found in the cytoplasm and sometimes attached to the endoplasmic reticulum -ribosome. In the translation process, those ‘codes’ of nitrogen bases are ‘translated’ or decoded into amino acids that make a polypeptide.