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.
Define Methods of Estimation of Ascorbic Acid (Vitamin C)? Ascorbic acid is also known as vitamin C which is a water soluble vitamin. As you already know, vitamins are a group
A fruit fly has four pairs of chromosomes in its cells. At meiosis, how many different combinations of maternal and paternal chromosomes are possible in the gametes?
The ability to maintain myocardial perfusion at constant levels in the face of changing driving presence is termed autoregulation. In normal cases, autoregulation is maintained at
Define Assessment of Manganese Status? The body Mn status has not been yet established by laboratory tests. Though the normal range of serum Mn concentration is found out to b
Acute Renal Failure You know that acute renal failure refers to the sudden deterioration in kidney function, characterised by reduced urine excretion to less than 10 ml/kg bo
Explain Acyclovir Available in topical, oral, and intravenous (IV) formulations, acyclovir is used to treat herpes simplex virus (HSV) and varicella-zoster virus (VZV) infectio
Q. Can you explain Yersinia Enterocolitica Gastroenteritis? Yersiniosis is an infectious disease caused by a bacterium of the genus Yersinia. Most human illness is caus
Define the Maintenance of Weight Loss? Once an individual has managed to lose weight to a desirable level, it must not be assumed that the weight loss will be maintained automa
Removable soft tissue-borne partial dentures have one of the lowest patient acceptance rates in dentistry. Those patients wearing the partial dentures often exhibit greater mobilit
Locomotory Structures Annelids possess three kinds of locomotory structures, namely parapodia, setae and suckers. Parapodia are segmentally arranged, lateral, hollow extensio
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