Already have an account? Get multiple benefits of using own account!
Login in your account..!
Remember me
Don't have an account? Create your account in less than a minutes,
Forgot password? how can I recover my password now!
Enter right registered email to receive password!
From Molecules to the First Cell
The prebiotic conditions on the earth in all probability were volcanic eruptions, lightning and heavy rains. There was no trace of free oxygen or an ozone layer in the atmosphere to absorb ultraviolet radiations from the sun. It is assumed that organic molecules would have originated in such climatic conditions. This is described as their abiotic origin. Laboratory experiments from 1953 onwards prove that organic molecules like amino acids, proteins, nucleotides, nucleic acids, lipids and ATP can be formed in similar conditions on the earth. Stan1r.y Miller's experiment described below is one such experiment (Fig. shown below). It is possible that such organic molecules similar to those synthesised in Miller's experiment would have got accumulated at several places in high concentration, giving rise to a kind of liquid soup.
Scientists have three different speculatiohs about the composition of a protobiont. Some consider it'as an aggregate of electrically charged molecules with water around them acting as a boundary and this is called as coacervate model (Fig. shown below). This model was proposed by Alexander Oparin. Sidney Fox proposed another model for protobiont formation called protenoid microsphere model. According to this model when water free mixtures of amino acids are heated at high temperature, they pol.yinerise to form protein-like molecules, called proteinoids. These can persist only if cooled quickly. According to a third model called as the lipid bilayer model of Richard Goldacre, an abiotically synthesised phospholipid bilayer was formed around a central space containing organic molecules. All such models are without any experimental or theoretical evidence. However, the supporters of each model try to explain how some life-processes like osmosis and budding, can be camed out by such protobionts.
Explain Chemistry and Occurrence of phytates? Most plant foodstuffs contain inositol which is present in the form of inyo-inositol hexakisphosphate i.e. phytic acid and its sal
Blood functions to maintain homeostasis in the human body through all but which of the following: Answer moving carbon dioxide away from cells following completion of aerobic metab
Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4
Which of the following is a true statement regarding the process of RNA editing? A. RNA editing changes the sequence of the mRNA message thereby permitting for enhance in prote
Explain Principle Osazone Test or Phenylhydrazine Reaction? Phenylhydrazine reacts with carbonyl compounds in neutral or slightly acidic medium to give phenylhydrazones. These
Cornea - Organogenesis of Eye and Limb The fully formed cornea contains 2-cell layered epithelium and the stroma made of extra cellular secreted materials. The bulk of the
Prevention of perinatal transmission Zidovudine alone, started at 14-34 weeks of gestation and continued in the infant for the first 6 weeks of life, reduced HIV transmission
Together, genomics, proteomics and transcriptomics are influential approaches to enhancing our understanding not only of how cells function normally but also what the key modificat
This problem refers to the MN and ABO loci mentioned in class. It also refers to the Rh locus, which is responsible for the positive/negative part of the blood type. The Rh+ allele
Define the properties of solutions Several properties of solutions are particularly important in food preparations. Amongst these are colligative properties, such as vapour pre
Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!
whatsapp: +91-977-207-8620
Phone: +91-977-207-8620
Email: [email protected]
All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd