Physico-Chemical Structure or Bonding Essay Example for Free

Physico-Chemical Structure or Bonding Essay Hydrogen bond is one of the most essential concepts in supramolecular chemistry or molecular sociology. It has significant ramifications on molecular biology and materials science. The term and concept ‘hydrogen bond’ has only emerged after 1930; however the general notion of weak but specific interaction that involves hydrides is much older (Webmaster 2005). Hydrogen bond refers to the attractive force between the hydrogen that has attached to an electronegative atom of a molecule and an electronegative atom of an unlike molecule. It is a special case of dipole forces wherein the electronegative atom is usually an oxygen, nitrogen or fluorine—elements that have a partial negative charge, except for hydrogen which possesses a partial positive side (Ophardt c. 2003). Hydrogen bonding happens when two electronegative atoms, for instance nitrogen and oxygen, interact with the same hydrogen. Normally, the hydrogen is covalently attached to an atom which is referred as the donor. But it interacts electrostatically with the other, known as acceptor. The interaction is primarily because of the dipole amid the electronegative atoms and proton (Day 1996). It is the strongest molecular force and passes on some strange properties to a myriad of substances namely water, proteins and nucleotides (Structure and Bonding: The Hydrogen Bond n. d. ). Hydrogen bond is one of the most important components of biological life. If there is no hydrogen bond, there will be no life because it holds the double helix of deoxyribonucleic acid (DNA) together (Emsley 2000). Hydrogen forms and structures covalent bonds with other molecules to produce and make molecules that are stable than the free atoms. The electron of the hydrogen is shared between the hydrogen and the atom to which it is bonded. The other electron from the bonded atom is also shared between the two (The Structure of DNA n. d. ). It is done through charge attractions. If hydrogen is bonded to oxygen or nitrogen, it evolves to be slightly positive charged. That fact allows the hydrogen bond to attract a center of negative charge on another molecule—it can be another oxygen or another nitrogen atom. Thus the hydrogen bond is written such as O-H=N (= signifies hydrogen bond). There are O-H=O or N-H=O and N-H=N—it is the weakest bond (Emsley 2000). That is the effect of hydrogen bonds on DNA. On the other hand, there is a study that has been conducted by Eric Kool, a professor of Chemistry from the University of Rochester, wherein a finding has been implied that â€Å"hydrogen bonds are not the key to DNA pairing after all† (Bradt 1997). The study suggests that it is more possible that the distinguishing and distinct shapes and sizes of each of the four DNA bases strengthen and suggest the 99. 9 percent accuracy of DNA replication. It has been illustrated like a space in a jigsaw puzzle wherein that space in the puzzle can only be filled by a piece that matches the shape of the space. That analogy means that there is only one base capable of squeezing into a DNA strand on its opposite given partner (Bradt 1997). According to Myron Goodman, a biologist and DNA expert from the University of Southern California, â€Å"the apparently inescapable conclusion is that hydrogen bonds (H-bonds) are not absolutely required,† this means that the results give a momentum and impetus to consider the role that the H-bonds play in stabilizing the DNA and enhancing the fidelity of DNA polymerase (Bradt 1997). Furthermore, there are still a number of factors that are responsible for the stability of the DNA double helix structure. Hydrogen bond is just among them. Although the hydrogen bond is weak, the millions of H-bonds showcase an extremely strong force that enables and keeps the DNA strand together (Rafael B. 2009). List of References Bradt, S. (1997) â€Å"Study: Hydrogen Bonds Aren’t Key to DNA Pairing After All. † Bio-Medicine [online] available from http://news. bio-medicine. org/biology-news-2/Study-3A-Hydrogen-Bonds-Arent-Key-To-DNA-Pairing-After-All-15262-1/ [13 February 2009] Day, A. (1996). â€Å"Hydrogen Bonds. † Birkbeck: University of London [online] available from http://www. cryst. bbk. ac. uk/PPS2/projects/day/TDayDiss/HBonds. html [13 February 2009] Emsley, J. (2000). â€Å"A New Way to Investigate the Hydrogen Bonds of DNA. † Science Watch [online] available from http://archive. sciencewatch. com/sept-oct2000/sw_sept-oct2000_page7. htm [13 February 2009] Ophardt, C. (c. 2003). â€Å"Intermolecular Forces: Hydrogen Bond. † El nhurst College: Virtual Chembook [online] available from http://www. elmhurst. edu/~chm/vchembook/161Ahydrogenbond. html [13 February 2009] Rafael B. (2009) â€Å"DNA Structure: Hydrogen Bonds. † Bright Hub [online] available from http://www. brighthub. com/science/genetics/articles/23384. aspx [13 February 2009] Structure and Bonding: The Hydrogen Bond. n. d. Prince Georges Community College [online] available from http://academic. pgcc. edu/~ssinex/struc_bond/hydrogen_bond. htm [13 February 2009] The Structure of DNA. n. d. Cambridge University [online] available from http://www-outreach. phy. cam. ac. uk/camphy/dna/dna11_1. htm [13 February 2009] Webmaster. (2005). â€Å"The Hydrogen Bond. † Gottingen University [online] available from http://www. hbond. de/ [13 February 2009]