Answer to Question #71472 in General Chemistry for Peter

Question

Give 4 physical properties of water that occur due to its polarity?
What form of bonding stabilises the favoured B helix of DNA that isn’t generally encountered in proteins?
Why does the size of the amino acids’ side chains determine the protein secondary structure?

Answer 1

1. Due to the high dielectric constant, water has a greater dissolving and dissociating ability than other liquids (attraction to polar molecules).
The specific heat of water is extremely large in comparison with the heat capacity of other bodies.
The freezing point of water decreases with increasing pressure, but does not increase, as one would expect.
The lower density of ice (when the water is heated from 0 to 4 ° C, its volume does not increase, but decreases, and its maximum density is not reached at the freezing point (0 ° C), but at 4 ° C (more precisely, 3.98 ° C) ).
A high evaporation temperature (at 100 °C turns into a gaseous state).
2. A double helix is a DNA polymer from a nucleic acid that is held by the nucleotides of which the base pair is together.
3. The secondary structure of the protein is a way of laying a polypeptide chain into a more compact structure, at which peptide groups interact with the formation of hydrogen bonds between them. There are two types of such structures - the packing of protein in the form of a rope and in the form of an accordion. The formation of the secondary structure is caused by the desire of the peptide to accept a conformation with the greatest number of bonds between the peptide groups. The type of secondary structure depends on the stability of the peptide bond, the mobility of the bond between the central carbon atom and the carbon of the peptide group, and the size of the amino acid radical.All this, combined with the amino acid sequence, will subsequently lead to a strictly defined protein configuration.