Introduction to viruses: For centuries submicroscopic organisms, also known as viruses, that grow and multiply at different rates inside of a cell, have been circulating our planet. Viral particles posses either DNA strands or RNA strands, but never both in contrast bacterial infections contain both. Many viruses have a membranous envelope that covering their capsid. The question of whether or not a virus is a living object or a complex protein is often fuzzy. When isolated from a host cell, a virus is unable to replicate, produce energy, or any other activities required for life.
As tough as it may be to tell a young child how babies are made, it does not compare to the complexity of explaining how the entire universe began. Every human has a natural desire to discover the truth, but it stands as one of the most controversial subjects. Others, Creationists, believe life and matter. The oldest rocks on Earth found to date are the Acasta Gneisses in northwestern Canada near the Great Slave Lake, which are four point three billion years old. The study of the origin of life on Earth, more specifically abiogenesis, is the natural process of life arising from non-living matter. Life on Earth is believed to have began from organic compounds about three point eight to four billion years ago.
The origin of life on Earth is a scientific problem which is not yet solved. There are many ideas , but few clear facts. Most experts agree that all life today evolved by common descent from a single primitive lifeform. This is in accord with the philosophy of naturalism : only natural causes are admitted.
In: Science. A theoretical approach to describe the mechanisms of the isomerization and reduction of a double bond, involved in the lanosterol conversion to cholesterol was undertaken. Ab initio calculations were performed in order to prove these mechanisms. Two different characteristics involved in this biosynthesis were explained, namely i the stability of each molecule during this reaction using total energy, hardness and dipole moment, and ii the explanation of proposed mechanisms [Steroid Biochemistry and Pharmacology, , p.