Chapter 21, Problem 7A

Interpretation Introduction

Interpretation:

The difference between hydrophobic and hydrophilic side chains needs to be explained and the solvent present in the body for proteins needs to be determined.

Concept introduction:

Hydrophobic- in amino acid structure, the side chains are composed mostly of carbon and hydrogen. They show the dipole moment and tend to be repelled from water, which is termed as hydrophobicity of amino acids.

Hydrophilic- the water-loving property of amino acid is termed as hydrophilic property. The polarity of amino acid is due to the presence of functional groups in the structure of amino acid.

Answer to Problem 7A

The hydrophobic amino acids are non-polar and the hydrophilic amino acids are hydrophilic.

Water is the universal solvent and it forms the natural environment for proteins in the body.

Explanation of Solution

Hydrophilic	Hydrophobic
Hydro= water, philic= loving.	Hydro=water, phobic= fear.
The polar groups are attracted to the water.	The non-polar groups are repelling the water molecules.
Hydrophilic amino acids are water-soluble.	Hydrophobic amino acids are water0insoluble.
Example-lycine, arginine, histidine.	Example- glycine, valine, leucine.

Water is used as a universal solvent. It has a dissolving capacity more than other solvents.

Water is present in a higher amount in the human body. Water is used as a solvent to forms a natural environment for proteins. Proteins are known as building blocks for the human body.

The majority functions of proteins are completed in the presence of water.

Conclusion

The hydrophilic and hydrophobic properties of the amino acid are represented by the different functional groups and side chains attached to the central carbon of the amino acid. The natural environment for the proteins is possible in the presence of water.