Textbook Problem

Answers to all problems are at the end of this book. Detailed solutions are available in the Student Solutions Manual, Study Guide, and Problems Book.

The Principle of Molecular Recognition Through Structural Complementarity Biomolecules interact with one another through molecular surfaces that are structurally complementary. How can various proteins interact with molecules as different as simple ions, hydrophobic lipids, polar but uncharged carbohydrates, and even nucleic acids? (Section 1.41)

Interpretation Introduction

To explain:

How proteins interact with various biomolecules through molecular surfaces which are structurally complementary.

Introduction:

Proteins are made up of amino acids. Diversity of these amino acids is the key feature that enable proteins to interact with other biomolecules with various kinds of characteristics. Some amino acids are nonpolar (alanine, cysteine, glycine, isoleucine, leucine); they are very important in forming hydrophobic interactions. There are polar amino acids (serine, threonine, cysteine, asparagine, glutamine, and tyrosine); they involve in dipole-dipole interactions and H bonding. These polar amino acids are very important in forming interactions with polar carbohydrates. There are charged amino acids depending on the physiochemical pH value.

Explanation of Solution

Structural features that are formed as a result of diversity of the building blocks (amino acid) of proteins enable them to form interactions with various kinds of chemical species. For an example lysine and arginine (+ charge), aspartate and glutamate (- charge) can get charged based on the pH value of the medium. Thus, they can interact with charged species. Nucleic acids consist of pentose sugars, phosphate groups and nitrogenous bases. In general, nucleic acids interact with proteins forming various deferent interactions that includes hydrogen bonding, electrostatic interactions as well as dipole-dipole interactions.

When a protein is made up with the incorporation of various amino acids, they provide unique structural properties for the protein. Thus, they can interact with various biomolecules through these structural features.