BIOCHEMISTRY - Textbook - Ostapchenko L. I. - 2012

Chapter 3. THE CELL AND EXTRACELLULAR MATRIX

3.1. Molecular and Supramolecular Organization of the Cell

It is generally accepted that all prokaryotic and Eukaryotic Cells evolved from a common ancestral Cell through two main Evolutionary Processes: random alterations in Genetic information and the Selection of that genetic information which ensures a higher level of viability for its bearer. It is directly impossible to observe the unique molecular events that occurred 3.5–4 billion years ago. However, one can analyze many "traces" of those ancient events—such as fossil Bacteria, plants, and animals—while the genetic information of modern organisms also preserves records of the living past, and so on.

Based on our current understanding of life, it can be hypothesized that the critical event in The formation of the primitive cell was The Development of the outer (now plasma) membrane, which created the first "cellular compartment"—a closed volume. It could have formed during Cell Evolution from amphipathic molecules (possessing both hydrophilic and hydrophobic regions) capable of spontaneously aggregating to form vesicle-like "cells." Only within such a confined volume could primitive molecules, similar to present-day Ribonucleic Acids, exert an influence on cellular traits. The described evolutionary pathway for the Formation of the primordial cell seems convincing, although alternative views do exist.