Biochemical origin of life - modern concept, PL-SQL Programming

BIOCHEMICAL ORIGIN OF LIFE -

  • It is generally agreed by astronomers, geologists and biologists that the earth is approximately 4500-5000 million years old.
  • It is an opinion of a large section of biologists that the original state of the earth bore little resemblance to its present day and had the following probable appearance:
  • It was hot about 4000-8000°C and as it cooled, carbon and the less volatile metals condensed and formed the core of the earth.
  • The surface was probably barren and rugged as volcanic activity, continuous earth movements and contraction on cooling, folded and fractured the surface.

1924_biochemical origin of life.png

  • The atmosphere is believed to have been totally different in those days.
  • The lighter gasses hydrogen (H), helium (He), nitrogen (N), oxygen (O) and argon (Ar) would have escaped because the gravitational field of the partially condensed planet would not contain them..
  • But simple compounds containing these elements would have been retained e.g., water (H2O), ammonia (NH3), carbon dioxide (CO2), methane (CH4), and until the earth cooled below 100°C all water would have existed as vapour. 
  • First molecular compound formed were H2O & NH3.
  • First organic compound formed was CH .
  • Free oxygen was absent. Therefore primitive atmosphere was reducing.
  • The chemical theory of life was elaborated by two workers independently.
  • A. I. Oparin (1923) and J.B.S. Haldane (1929) and was summarized by oparin in his book "The origin of life".
  • They held that Spontaneous generation of life under the present environment conditions is not possible.
  • Earth's surface and atmosphere during the first billion years of its existence were radically different form today's conditions.
  • Earth's initial atmosphere was a reducing one.
  • The first life arose from a collection of chemical through a progressive series of chemical reactions in which atoms combined into inorganic molecules, inorganic molecules into simple organic compounds, and simple organic compounds into complex organic compounds, which finally got organized into the living matter.
  • The sequence of changes an 8 step process, begins right from the formation of earth.

 

2346_biochemical origin of life1.png

  • Solar radiation, heat radiated by earth and lightning provided energy for evolution of molecules.
  • The Oparin-Haldane theory was experimentally supported by Stanley Miller in 1952.
Posted Date: 10/8/2012 8:44:06 AM | Location : United States







Related Discussions:- Biochemical origin of life - modern concept, Assignment Help, Ask Question on Biochemical origin of life - modern concept, Get Answer, Expert's Help, Biochemical origin of life - modern concept Discussions

Write discussion on Biochemical origin of life - modern concept
Your posts are moderated
Related Questions
SQL outer join SELECT * FROM IS_CALLED NATURAL LEFT JOIN IS_ENROLLED_ON Note that adding LEFT to an invocation of CROSS JOIN has no effect unless the right-hand operand

Project Description: I want a database for large governmental and private data sets on one country that will be easily extended to other countries in the future. Also, the datab

We are seeking a freelance consultant that is familiar with Appgen applications. We require exporting all our data into a format appropriate for importing into SAP Business One. Pl

Equivalences & Rewrite Rules: If notice that as well as allowing us to prove trivial theorems, and tautologies enable us to establish that certain sentences are saying the sam

PITS Depressions in secondary cell wall is called pit. A pit present on the free cell wall surface without its partner is called Blind pit. It consists of 2 parts -

User-Defined Exceptions The PL/SQL defines the exceptions of your own. Dissimilar to the predefined exceptions, the user-defined exceptions should be declared and should be rai

Using RENAME in combination with JOIN - SQL Example gives pairs of ids of students having the same name, by joining two renamings of IS_CALLED. Example gives an equivalent ex

Accessing Attributes: You can refer to an attribute only by its name not by its position in the object type. To access or modify the value of an attribute, you can use the dot

Use the NOCOPY Compiler Hint By default, the OUT and IN OUT parameters are passed by the value i.e. the value of an IN OUT actual parameter is copied into the corresponding fo

Use of Table Expressions - Expressing Constraint Conditions With the exception of key constraints, the examples in the theory book all explicitly reference at least one relvar