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
Effects of NULL for Table Expression Here's an important distinction between expressions denoting tables and expressions denoting multisets of rows: a table expression cannot

Parameter Modes: You do not require to specify a parameter mode for the input bind arguments (those used, for illustration, in the WHERE clause) as the mode defaults to IN. Th

Declaring a Cursor The Forward references are not allowed in the PL/SQL. Therefore, you must declare a cursor before referencing it in other statements. Whenever you declare a

Map and Order Methods: The values of the scalar datatype like CHAR or REAL have a predefined order that allows them to be compared. While, the instances of an object type has

ORIGIN OF EARTH - BIG-BAN G HYPOTHESIS - Origin of life is linked to origin of earth. Cosmos, the Universe originated 10-20 billion years ago by Big Bang (thermonu

BEGIN Parameter Description in pl sql: BEGIN: This keyword signals the beginning of the executable section of a PL/SQL block, that contains executable statements. The execut

Example of COALESCE operator Example: Give the total of marks for each exam (simplified solution) SELECT CourseId, COALESCE ((SELECT SUM (Mark) FROM EXAM_MARK AS EM

WHILE-LOOP The WHILE-LOOP statement relates a condition with the series of statements enclosed by the keywords LOOP and END LOOP, as shown: WHILE condition LOOP sequence_of_sta

I would like to have a custom MS Access database designed and coded that would help me schedule my customer's orders and that would help me track my employees production output and

Tautology - Equivalences Rules: If there Tautologies are not all the time as much easy to note as the one above so than we can use these truth tables to be definite that a sta