tailieunhanh - Non-Covalent Bonds (Weak Bond)

When operators drill oil and gas wells, they typically remove topsoil from the well site and lay a well pad, where the drilling rig is located. Other equipment on site can include generators and fuel tanks. In addition, reserve pits are often constructed to store or dispose of water, mud, and other materials that are generated during drilling operations, and roads and access ways are often built to move equipment to and from the wells. Generally, these activities can degrade the environment in three ways: • Air quality. Newly graded roads can produce dust, impairing air quality and visibility. | Non-Covalent Bonds Weak Bond Weak bonds are those forces of attraction that in biological situations do not take a large amount of energy to break. For example hydrogen bonds are broken by energies in the order of 4 - 5 kcal mol. van der Waals interactions have energies around Kcal mol. In biological systems ionic bonds hydrogen bonds and van der Waals interactions are considered weak bonds Weak Bonds conti. Weak bonds may be easily broken but they are very important because they help to determine and stabilize the shapes of biological molecules. For example they are important in stabilizing the secondary structure alpha helix and beta pleated sheet of proteins. Hydrogen bonds keep complementary strands of DNA together. Hydrogen bonds participate in enzyme catalysis Types of Intermolecular Forces Hydrogen Bond strongest The hydrogen bond is a special dipole-dipole interaction between the hydrogen atom in a polar N-H O-H or F-H bond and an electronegative O N or F atom. IT IS NOT A BOND. A H B or A H A A B are N O or F .