How do functional groups affect the properties of biological molecules?

Functional groups determine the chemical behaviour and properties of biological molecules by influencing their reactivity and interactions.

Functional groups are specific groups of atoms within molecules that are responsible for the characteristic chemical reactions of those molecules. They are like the special teams in a game of football, each having a specific role that affects the outcome of the game. In the same way, functional groups in biological molecules determine how these molecules will react and interact with other molecules, thus influencing their properties.

For instance, the hydroxyl group (-OH) is a common functional group found in many biological molecules such as carbohydrates and alcohols. This group is polar due to the electronegativity difference between oxygen and hydrogen, making compounds with this group soluble in water. This solubility in water is crucial for biological molecules as it allows them to be transported in the body and participate in metabolic processes.

Another example is the carboxyl group (-COOH) found in amino acids, the building blocks of proteins. This group can donate a proton (H+) in solution, making it acidic. This acidity plays a crucial role in protein structure and function, as it influences the charge distribution on the protein surface, affecting its interactions with other molecules.

The amino group (-NH2) is another functional group found in amino acids. It can accept a proton and act as a base. The ability of amino acids to act as both acids and bases due to these functional groups is fundamental to their role in protein synthesis.

In summary, functional groups are key determinants of the properties of biological molecules. They influence the reactivity, solubility, acidity or basicity, and ultimately the function of these molecules in biological systems. Understanding the role of functional groups is therefore essential in the study of biochemistry.