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Applications of Bio mimicry Incredible applications of Bio mimicry The ability of geckos − which can hang on a glass surface using only one toe − to climb on sheer surfaces has been attributed to the van der Waals forces between these surfaces and the spatulae (microscopic projections) which cover the hair−like setae found on their footpads. There has been a wide range of application of synthetic setae, also known as “gecko tape”, ranging from nanotechnology and military uses to health care and sport. Thus, gaining knowledge towards chemical bonding helps to investigate much more real−life applications.

Learning Objectives

After completing the topic, the student will be able to:

  • Define and understand the concept of chemical bonding.
  • Analyze and examine how atoms combine to form molecules and compounds.
  • Understand and explore the basis for formation of molecules and how they enable chemical bonding between atoms.
  • List different types of bonds that occur between elements.
  • Define and distinguish single, double, and triple bonds.
  • Compare and analyze the relative strengths of ionic, covalent, and hydrogen bonds.
  • Define and distinguish polar covalent bonds and non−polar covalent bonds.
  • Define and discuss van der Waals attractions and analyze how these forces influence some of the biomimicry applications.
  • Appreciate and analyze how molecular shape is crucial in biology.
  • List the chemical reactions in everyday life.
Chemical bond Chemical bond- Attraction between atoms A chemical bond is an attraction between atoms that allows the formation of chemical substances that contain two or more atoms. The bond is caused by the electromagnetic force attraction between opposite charges, either between electrons and nuclei, or as the result of a dipole attraction. The strength of chemical bonds varies considerably; there are "strong bonds" such as covalent or ionic bonds and "weak bonds" such as dipole−dipole interactions, and hydrogen bonding.
What is Chemical Bonding?

A bond is formed when two atomic nuclei attract the same electrons. Energy is released when a bond is formed, and energy must be supplied to break a bond. Atoms bond to acquire a stable configuration, a completed outer shell. The atoms in molecules, crystals, metals, diatomic gases and most of the physical environment around us are held together by chemical bonds.

Molecular shapes, the three−dimensional arrangements of the atoms that constitute – a molecule are determined by the nature of bonds between atoms in a molecule. Molecular geometry determines several properties of a substance including its reactivity, polarity, phase of matter, color, magnetism, and biological activity and hence there is no topic more fundamental to Chemistry than the nature of the chemical bond.

The molecular shapes define all the life processes right from the way a biological "cell" works, the way nerve impulses are communicated and the way immune system works. Genes function when certain nucleic acid molecules fit into specific regions of other nucleic acid. Hydrogen bonding, for example, plays an important role in determining the three−dimensional structures adopted by proteins and nucleic bases.

In these macromolecules, bonding between parts of the same macromolecule causes it to fold into a specific shape, which helps determine the molecule\'s physiological or biochemical role. The double helical structure of DNA, for example, is due largely to hydrogen bonding between the base pairs, which link one complementary strand to the other and enable replication.

Nucleotides Nucleotides are held together by hydrogen bonds. The molecular shapes define all the life processes. The double helical structure of DNA, is due largely to hydrogen bonding between the base pairs, which link one complementary strand to the other and enable replication.
Examples of Chemical Bond

The formation and function of molecules depend on chemical bonding between atoms. Now that we have looked at the structure of atoms, we can move up the hierarchy of organization and see how atoms combine to form molecules and ionic compounds.

Atoms with incomplete valence shells can interact with certain other atoms in such a way that each partner completes its valence shell: The atoms either share or transfer valence electrons. These interactions usually result in atoms staying close together, held by attractions called chemical bonds.

The strongest kinds of chemical bonds are covalent bonds and ionic bonds. Ionic bond refers to electrostatic forces that exist between ions of opposite charge which are formed from atoms by the transfer of one or more electrons from one atom to another. Ionic bonds are observed in the interaction of metals with non–metals.

Covalent bonding involves sharing of electrons in which the positively charged nuclei of two or more atoms simultaneously attract the negatively charged electrons that are being shared between them. Sodium chloride (Table salt) is an example of ionic bond between sodium and chlorine ions where as covalent bonds hold the atoms together in the sugar molecules.

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