The importance of Hydrogen Bonding in Biology Essay

The importance of Hydrogen Bonding in Biology - Essay Example The atom that covalently links to the hydrogen is the hydrogen bond donor and the other atom represent the hydrogen bond acceptor. These atoms have lone pair of electrons and a negative partial charge that enable them form this bond with hydrogen. Orphardt explains that hydrogen carries a partial positive charge. The formation of a hydrogen bond requires that hydrogen get attracted to an atom that has a partial negative charge. Orphardt explains that hydrogen bond is a directional bond this means the strength of a hydrogen bond relies on its alignment with two electronegative atoms (Orphardt, 2003). Hydrogen Bonding in Water Hydrogen bond is important in that it determines the physical and chemical properties of polar substances for example water. Water has a simple molecular structure consisting of two hydrogen atoms and the atom of oxygen. The hydrogen atoms covalently bond with the oxygen atom. The oxygen atom contains two lone pairs of electrons. The partial positive charge prese nt on the hydrogen atom together with the partial negative charge present on the oxygen atom gives water its polar characteristic. This attractive force between the oxygen atom and the hydrogen atoms result in the formation of a hydrogen bond. The polarity of water makes it a good solvent it allows polar substances and ions to dissolve in water. The polarity in water allows high cohesive force to exist in water molecules. One water molecule can form a hydrogen bond with other four water molecules. The high cohesion between water molecules allows water to be drawn up the xylem vessels in plants Hydrogen bonds bind water molecules together constantly form and break; therefore, changing the temperature of water requires the constant addition or removal of heat. This makes water have a high specific heat capacity water and favourable in preventing temperature changes in the body. The hydrogen bonds in water are responsible for the high surface tension in water. The hydrogen bonds hold w ater molecules tightly at the surface. This allows dense substances to float in water and for insects to walk on water Hydrogen Bonding in DNA Structure The hydrogen bonds determine and stabilize the structure of macromolecules such as proteins, nucleic acids. The hydrogen bond is responsible for holding together the three-dimensional structures of proteins and DNA. Hydrogen bonds are responsible for formation of biological structures such as double helix DNA strand. The hydrogen bond plays a critical role in ensuring the DNA structure is stable. Hydrogen bonding in a DNA structure is the chemical interaction responsible for base pairing. Arnold states that hydrogen bond holds together the double helix structure. The base pairs in DNA and RNA strands are connected by hydrogen bonds. The DNA molecule consists of four bases cytosine, guanine, thymine, and adenine. The DNA double helix structure has two polynucleotide strands that are intertwined together. The DNA structure is very sta ble because of DNA base pairs arrangement, which allows the interaction of the bases (Arnold, 2009). Hydrogen bonding is significant in holding together the polynucleotide strands of DNA. An adenine on one-strand pairs with a thymine base on the other strand and a guanine pairs with cytosine. Arnold describes that the stability of a double helix DNA strand is due to the internal and external hydrogen bonds existing between the complementary nucleotide base pairs. Arnold