Coacervates & Microspheres

Coacervates

Oparin(1924)observe that if a mixture of a large protein and a polysaccharide is shaken,coacervates are formed.The coacervates contain mainly protein , polysaccharides and some water.Oparin's coacervates also show a sinpsi form of metabolism.As these Coacervates do not have lipid outer membrane hence they can't reproduce.Thus they do not fulfil the requirement for probable precursors of life.

Microspheres

When mixtures of artificially produced organic compounds are mixed with cool water microspheres are formed. If the mixture contains lipids, the surface of the microspheres consists of lipid bilayer, reminiscent (remembering things of past) to the lipid bilayer of cell membranes. Sydney Fox (1950) heated a mixture of 18 amino acids to temperatures of 130 to 180°C. He obtained stable protein like macromolecules which he named proteinoids. When the proteinoid material was cooled and examined under microscope, Fox observed small spherical cell-like units that had arisen from aggregations of proteinoids. These molecular aggregates were called proteinoid microspheres. The first non-cellular forms of life could have originated 3 billion years back. They would have been giant molecules (RNA, Proteins, Polysaccharides etc.). 

1 Physical properties of proteinoid microspheres.

 They were spherical, microscopic with about I to 2 um in diameter, similar to the size and shape of coccoid bacteria.

 Structural properties of proteinoid microspheres.

Under electron microscope, con- centric double layered boundries around them have been observed through which diffusion of material occurs. They have the ability of motility, growth, binary fission into two particles and a capacity of reproduction by budding and fragmentation. Superficially, their budding resembles with those of bacteria and fungi.

Enzyme like activity of protenoid microspheres

They have been found to have catalytic activity,such as degradation of glucose.This enzymatic activity of protenoid microspheres is particularly lost during heat.