Chapter U2.21, Problem 1E

Interpretation Introduction

Interpretation : An amino acid is to be described.

Concept Introduction : Our body is made of many types of molecules. There are some body building molecules called amino acids.

Answer to Problem 1E

Amino acids are the building materials for many structures in our body especially those linked to functioning of cells. Important features of amino acids are as follows:

1. They have two functional groups; an amine group and a carboxyl group.
2. General formula of an amino acid is C₂H₄NO₂R, where R is a general placeholder for a variety of groups of atoms.
3. They have mirror image isomers.
4. There are 20 different amino acids needed by our body.
5. Some amino acids are hydrophobic and some are hydrophilic.
6. The amino acids link with each other to form peptide bonds.

Explanation of Solution

Amino acids are the building materials for many structures in our body especially those linked to functioning of cells. Important features of amino acids are:

1. They have two functional groups; an amine group and a carboxyl group.
2. General formula of an amino acid is C₂H₄NO₂R, where R shows variety of groups of atoms. R can be hydrogen and carbon and sometimes contain nitrogen/ oxygen.
3. They have mirror image isomers as the central carbon atom is attached to four different groups. Only the left handed amino acid molecules are used by the human body.
4. There are 20 different amino acids needed by our body. Our body produces only 6 amino acids; rest is taken in through food.
5. Some amino acids are hydrophobic; that is they are nonpolar. They have only carbon and hydrogen atoms in the R group. Some amino acids are hydrophilic; that is they are attracted by water. The R group of such amino acids contains nitrogen and oxygen.
6. The amino acids link with each other to form peptide bonds. The carboxyl group of one amino acid link with the amine group of another amino acid to form a peptide bond. In this way long chain of amino acids is formed called protein. Amino acids can be linked in a variety of manner so a variety of protein molecules are available.

Conclusion

Amino acids are building blocks of our cells. Our body produces only 6 amino acids; rest is taken in through food.