Interaction with water

The structural and electrical properties of the water molecule are discussed in ‘The water molecule and its interactions.’ Two hydrogen atoms are joined by covalent bonds to one oxygen atom to form a water molecule. Hydrogen bonding is a sort of interaction in which water molecules interact with one another. The key to comprehending water is a tetrahedral configuration of four water molecules surrounding a central one. It aids in the understanding of the structure of water in various states, its properties, and how it interacts with other molecules, enabling for the investigation of the properties and behaviour of a wide range of chemical, physical, and biological systems involving water.

Water interaction properties

Water is regarded as the universal solvent since it dissolves not just a wide range of chemicals but also more substances than any other liquid. It dissolves ions and polar molecules quickly as a polar molecule with partially positive and negative charges. 

As a result, water is referred to as a solvent: a material that can dissolve other polar molecules and ionic compounds. These molecules’ charges establish hydrogen bonds with water, encasing the particle in water molecules. A hydration shell, also known as a hydration sphere, keeps the particles separated or disseminated in the water.

Individual ions interact with the polar regions of water molecules during the dissociation process, disrupting their ionic bonds, when ionic substances are added to water. When atoms or groups of atoms separate from molecules to produce ions, this is known as dissociation. 

When NaCl crystals are introduced to water, the molecules of NaCl break into Na⁺ and Cl⁻ ions, and hydration spheres develop around the ions. The partially-negative charge of the oxygen in the water molecule surrounds the positively-charged sodium ion; the partially-positive charge of the hydrogen in the water molecule surroundings the negatively-charged chloride ions

Dissociation of NaCl in water

When table salt (NaCl) and water are combined, hydration spheres form around the ions. Water rapidly dissolves hydrophilic substances because many molecules are polar or charged. Water, on the other hand, is a poor solvent for hydrophobic molecules like lipids. When nonpolar molecules interact with hydrophobic molecules in water, the water modifies its hydrogen bonding patterns around the hydrophobic molecules, forming a clathrate-like structure. The overall entropy of the system decreases dramatically as the hydrogen-bonding pattern of the water solvent changes, as the molecules become more ordered than in liquid water. A huge fall in entropy is not spontaneous in thermodynamic terms, and the hydrophobic molecule will not dissolve.

Nucleic acid interaction with water

The interaction of proteins with DNA strands was first identified microscopically in the late 1800s. Since then, researchers have demonstrated that proteins interact with DNA and RNA to impact the structure and function of the corresponding nucleic acid using a range of in vitro and in vivo tests. Understanding the functions of protein–nucleic acid complexes in the regulation of transcription, translation, DNA replication, repair, and recombination, RNA processing, and translocation is revolutionising our understanding of cell biology, normal cell development, and disease causes. This article introduces some of the most important approaches for studying protein–nucleic acid interactions.

Phosphate group, ribose sugar, and nitrogenous base are the three primary components of DNA. Phosphate and ribose sugar are both hydrophilic, or water-loving. The nitrogenous base is in the middle of the pack; it may hydrogen bind but dislikes water. DNA will create a double helix if given the chance (base pairing) (generally with 2 strands). The only difference is that RNA uses only one strand. The nitrogenous bases (AGTC) are moved out of the water and into the core of the double helix, where they don’t have to interact with it as much.The short explanation is that nucleic acids will form double helices in water (if they can) in order to get their more hydrophobic regions out of the water. The bases, on the other hand, are not necessarily hydrophobic, but they aren’t as hydrophilic as the rest of the body.

Lipids interact with water

The connection between the oxygen and hydrogen atoms in a water molecule results in a polar covalent bond (see our module Water: Properties and Behavior). Because oxygen atoms have a higher pull on electrons than hydrogen atoms, the electrons that form this link are shared unequally amongst the atoms. This results in a slight negative charge on the oxygen end and a slight positive charge on the hydrogen end of the water molecule.

The connection between carbon and hydrogen atoms in lipids, on the other hand, is not polar. This is due to the fact that the electrons in covalent bonds are equally divided between the carbons and hydrogens, and there are no partial charges whatsoever. As a result, a nonpolar molecule is formed by lengthy chains of carbon-hydrogen bonds.

Because “like attracts like,” the variations in bonding between water and lipid molecules are significant. Water tends to dissolve compounds with polar bonds, such as salt and sugar, because it is a polar solvent. Because there is no charge on the nonpolar molecule to attract the polar molecule, nonpolar molecules do not dissolve in polar liquids. Polar liquids mix with other polar liquids to dissolve polar or charged solutes; nonpolar liquids mix with other nonpolar liquids to dissolve nonpolar solutes (the material that is dissolved).

Conclusion

The water molecule and its interactions.’ Two hydrogen atoms are joined by covalent bonds to one oxygen atom to form a water molecule. It aids in the understanding of the structure of water in various states, its properties, and how it interacts with other molecules, enabling for the investigation of the properties and behaviour of a wide range of chemical, physical, and biological systems involving water.