Relationship between Structure and Function of Molecules

Carbon chains form the foundational structure, or skeleton, of organic molecules, serving as the backbone upon which different atoms can be attached. These attached groups, known as functional groups, consist of specific combinations of atoms that exhibit consistent behaviour and reactivity patterns. Functional groups play a crucial role in determining the properties and characteristics of organic molecules.

Organic molecules, found in living organisms, such as sugars, fatty acids, amino acids, and nucleosides, typically possess a carbon backbone, along with one or more functional groups. These functional groups contribute to the unique properties and functions of these organic molecules, as they impart distinct chemical and physical properties, reactivity, and biological activities.

functional groups  

Hydrocarbon chains, which consist exclusively of carbon and hydrogen atoms, are considered hydrophobic, meaning they are repelled by water and do not readily mix or dissolve in water. This is because the carbon-hydrogen bonds are relatively non-polar, resulting in a lack of charge separation and, therefore, a low affinity for water molecules.

hydrophobic and hydrophilic hydrocarbons

On the other hand, functional groups, which are specific combinations of atoms attached to the hydrocarbon chains, can introduce polarity or charge to an organic molecule. Some functional groups have the ability to ionize, meaning they can either gain or lose a charged particle (such as a proton or an electron) in an aqueous environment. When a functional group ionizes, it can make the organic molecule hydrophilic, or water-attracting. This is because the charged or polar functional group can interact with water molecules through hydrogen bonding or other electrostatic interactions, allowing the organic molecule to dissolve or mix with water.