The Big Bang theory of the formation of the universe

1. All material in the universe was created in a huge "explosion," creating and defining matter and space. The sudden cooling of the superheated ejecta facilitated the combination of atomic components into atoms and molecules. These clouds of gasses eventually cooled and formed the principle components of galaxies - including stars and planets. The Big Bang theory of the formation of the universe

2. A. The earth formed approximately 4.6 BYA (billion years ago.) Initially, there was a cloud of gasses and dust particles, possibly originating from the ejected particles of a nearby supernova. B. The cloud gradually contracted and flattened, concentrating about 99% of its mass in the center with the rest rotating counterclockwise in a flattened disk. C. As the disk rotated, turbulence was created, causing condensation of the disk into small, turbular eddies. These gradually accreted together to form protoplanets. D. These protoplanets further accreted, creating the mature planets of the solar system. Formation of the solar system

3. Origin of life Oparin-Haldane hypothesis. • The atmosphere of the early Earth may have been chemically reducing in nature, composed primarily of • methane (CH4), • ammonia (NH3), • water (H2O), • hydrogen sulfide (H2S), • carbon dioxide (CO2) or • carbon monoxide (CO), and • phosphate (PO43-), with • molecular oxygen (O2) and • ozone (O3) either rare or absent. • In such a reducing atmosphere, electrical activity can catalyze the creation of certain basic small molecules (monomers) of life, such as amino acids. • This was demonstrated in the Miller–Urey experiment by Stanley L. Miller and Harold C. Urey in 1953. • Phospholipids (of an appropriate length) can spontaneously form lipid bilayers, a basic component of the cell membrane • These organics, accumulated in the surface waters of the ocean, forming a "primordial soup", out of which, in time, life in its most elementary form emerged

4. Oparin-Haldane model The steps of the Oparin-Haldane model are described below. • 1) Organic molecules including amino acids and nucleotides are synthesized abiotically (without living cells). • 2) Organic building blocks in the prebiotic soup are assembled into polymers of proteins and nucleic acids. • 3) Biological polymers are assembled into a self-replicating organism that fed on the existing organic molecules.

6. Diagram of the Miller-Urey apparatus Conducted in 1953 by Stanley Miller under the supervision of Harold Urey; the first experiment to test the Oparin-Haldane theory about the evolution of prebiotic chemicals and the origin of life on Earth. A mixture of methane, ammonia, hydrogen, and water vapor, to simulate the version of Earth's primitive, reducing atmosphere proposed by Oparin, was introduced into a 5-liter flask and energized by an electrical discharge apparatus to represent ultraviolet radiation from the Sun. The products were allowed to condense and collect in a lower flask which modeled a body of water on the Earth's surface. Heat supplied to this flask recycled the water vapor just as water evaporates from lakes and seas, before moving into the atmosphere and condensing again as rain. Miller-Urey Experiment

7. After a day of continuous operation, Miller and Urey found a thin layer of hydrocarbons on the surface of the water. After about a week of operation, a dark brown scum had collected in the lower flask and was found to contain several types of amino acids, including glycine and alanine, together with sugars, tars, and various other unidentified organic chemicals The conditions were: A gaseous phase containing reduced sources of carbon (methane), nitrogen (ammonia), oxygen atoms (water), and hydrogen atoms from any or all of these precursors as well as hydrogen gas. Electrical energy provided by spark discharge. Ambient temperature between 0 and 100 C. Sterile conditions to begin with (abiotic environment). Apparatus used in the Miller-Urey experiment Miller-Urey Experiment

8. microspheres • Fox was best known for his seminal experiments in the synthesis of thermal proteins (previously known as "proteinoids") from amino acids which he carried out in the 1960s and for his demonstration that these proteins, when placed in water, spontaneously self-organize into structures, known as microspheres, that resemble primitive cells. • His most recent experiments sought to demonstrate that the cell-like structures he created in the laboratory also act as protonerve cells

9. Microscopic, firm spherules which form on the cooling of hot saturated solutions of proteinoids. They were first reported in 1959 by Sidney Fox, K. Harada, and J. Kendrick who proposed that microspheres might represent a significant early stage in precellular evolution. It has been suggested that their greater stability makes them a better proposition in this regard than coacervates. One milligram of proteinoids can yield 100 million microspheres, ranging from 1.4 to about 2.5 microns in diameter. Microspheres have been observed to retain their form for several weeks and, when sectioned, may display a double-walled structure. Recently, Fox argued that microspheres also display characteristics of primitive nerve cells. Microspheres

10. Coacervates • Their name derives from the Latin coacervare, meaning to assemble together or cluster • Coacervates measure 1 to 100 micrometers across, possess osmotic properties, and form spontaneously from certain weak organic solutions • A spherical aggregation of lipid molecules making up a colloidal inclusion which is held together by hydrophobic forces. • It was suggested by Oparin that coacervates may have played a significant role in the evolution of cells. • In water, organic chemicals do not necessarily remain uniformly dispersed, but may separate out into layers or droplets. • If the droplets which form contain a colloid rich in organic compounds and are surrounded by a tight skin of water molecules then they are known as coacervates. • These structures were first investigated by Bungenburg de Jong in 1932. • A wide variety of solutions can give rise to them; for example, coacervates form spontaneously when a protein, such as gelatin, reacts with gum arabic.

11. Origin of life • Stage 1: The formation of the earth and atmosphere is considered the first stage in the long trek from inanimate matter to life. This stage provided the inorganic raw materials for the evolution of life and set up the conditions for their interaction. • Stage 2: The second stage produced organic molecules through interactions between inorganic substances, driven by energy sources such as lightning and ultraviolet radiation from the sun. • Stage 3: In the third stage, the organic molecules present assembled randomly into collections capable of chemical interaction with the environment. As the collections formed, interactions taking place within them produced still more complex organic substances, including polypeptides and nucleic acids. Some of these collections of molecules were capable of carrying out primitive living reactions. There is little agreement on the form taken by the first spark of life in these primitive aggregates.

12. Origin of life • Stage 4: In the fourth stage, a genetic code appeared in the primitive living aggregates. This code regulated duplication of information required for reproduction of the aggregates and established the link between nucleic acids and the ordered synthesis of proteins. Things were still pre-cellular, but with these developments (directed synthesis and reproduction), life was fully established in the molecular assemblages. • Stage 5: The fifth and final stage involves conversion of the pre-cellular assemblages into fully organized cells with a nuclear region and a cytoplasm, all enclosed by an outer boundary membrane--a plasma membrane.

13. Eukaryotic cells are actually the descendents of separate prokaryotic cells • Evidence supports the idea that eukaryotic cells are actually the descendents of separate prokaryotic cells that joined together in a symbiotic union. • In fact, the mitochondrion itself seems to be the "great-great-great-great-great-great-great-great-great granddaughter" of a free-living bacterium that was engulfed by another cell, perhaps as a meal, and ended up staying as a sort of permanent houseguest. • The host cell profited from the chemical energy the mitochondrion produced, and the mitochondrion benefited from the protected, nutrient-rich environment surrounding it. • This kind of "internal" symbiosis - one organism taking up permanent residence inside another and eventually evolving into a single lineage - is called endosymbiosis.