What is the importance of the dipole nature of water to the chemistry of life?

Question

What is the importance of the dipole nature of water to the chemistry of life?

Answer 1

The Nearly Universal Solvent
The water molecule has an asymmetrical shape, with the hydrogen atoms sitting like two ears on the larger oxygen atom. This leads to the molecule's having an asymmetrically distributed electric charge, with the ears charged positively and the other end negatively. This "dipole" is what makes water such a good solvent. Many substances, such as ordinary salt (NaCl) are held together not by covalent bonds but by electrical attraction "at a distance", without significant electron-sharing. This bond is called "ionic": Na is positively charged and Cl negatively, because the outermost electron of Na (sodium) is so weakly bound that Cl (chlorine) can "steal" it when they separate. The dipole nature of water molecules enables it to pull the NaCl molecules apart and to surround each component with a water coating - so the substance is dissolved.

Water's ability to dissolve so many materials makes it an excellent medium for transporting these materials, especially inside our bodies. It is no wonder that we are two-thirds water!

All the solid materials in the body (bones, fatty insulation of nerve and muscle fibres, etc.) have to be carefully "chosen" to be insoluble in water.

Water is also a good solvent due to its polarity. When an ionic or polar compound enters water, it is surrounded by water molecules (Hydration). The relatively small size of water molecules typically allows many water molecules to surround one molecule of solute. The partially negative dipole ends of the water are attracted to positively charged components of the solute, and vice versa for the positive dipole ends.

In general, ionic and polar substances such as acids, alcohols, and salts are relatively soluble in water, and nonpolar substances such as fats and oils are not. Nonpolar molecules stay together in water because it is energetically more favorable for the water molecules to hydrogen bond to each other than to engage in van der Waals interactions with nonpolar molecules.

An example of an ionic solute is table salt; the sodium chloride, NaCl, separates into Na+ cations and Cl- anions, each being surrounded by water molecules. The ions are then easily transported away from their crystalline lattice into solution. An example of a nonionic solute is table sugar. The water dipoles make hydrogen bonds with the polar regions of the sugar molecule (OH groups) and allow it to be carried away into solution.

Answer 2

Besides some of the very good answers rajeev gave, water is absolutely essential to the function of the biopolymers of life-- DNA, RNA, and proteins.

Just take proteins as an example. A protein is a very large molecule made of a string of various multiple amino acids. Each protein can take on millions if not billions of different conformations, but only one conformation of each type of protein can actively create all of the important organelles and cellular structures of life. The adoption of this conformation or "protein folding" takes mere nanoseconds in an aqueous environment as all of the amino acids, large or small, hydrophobic or hydrophilic, interact with each other and the water surrounding them to form the functional protein.

Answer 3

What Is Dipole In Chemistry

Answer 4

A couple of answers:

1. Because water molecules have a positive end and a negative end, water molecules tend to stick together (cohesion). This property allows for capillary action which helps water rise through thin tubes like xylem vessels.
2. Water has surface tension.
3. Water can dissolve many substances because it can pull on molecules with charges and pick them off to be distributed.

Answer 5

it gives water a character of cohesion and adhesion that give plants the ability to transport water over large distances...like a tree! without that character they would be unable to do so and plant size would be altered as would subsequent life on earth