The group linkage present in fats is: (a) Peptide linkage (b) Ester linkage (c) Glycosidic linkage (d) None of these

Lipids are a broad group of naturally occurring molecules which include fats, oils, waxes, certain vitamins (such as A, D, E and K), hormones, and most non-protein components of membranes. These molecules are unified by their hydrophobic (water-fearing) or amphipathic (containing both hydrophobic and hydrophilic regions) properties, which allows them to play crucial roles in biological structures and functions.

Lipids are primarily made up of long chains of hydrocarbons that end in a carboxyl group, which is a functional group featuring both a carbonyl and a hydroxyl group. This unique structure grants lipids the ability to create complex structures such as cellular membranes and to store energy. In the case of fats, specifically, they are structured with glycerol linked to three fatty acid chains, forming what is known as a triglyceride.

Fatty acids are carboxylic acids with a long aliphatic chain, which can be either saturated or unsaturated. These molecules are key components of lipids, like triglycerides and phospholipids. Saturated fatty acids lack double bonds between the individual carbon atoms, resulting in a straight chain that can stack tightly, making these types of fats solid at room temperature. On the other hand, unsaturated fatty acids contain one or more double bonds, creating kinks in the chain and preventing tight stacking, making them liquid at room temperature, like oils.

When discussing fatty acids in the context of fats, their role is pivotal as they determine the physical and chemical properties of the fat. The variation in the length of the carbon chain and the number of double bonds informs the melting point, nutritional value, and the role they play in biological processes.

Biomolecules are organic molecules that are intricately involved in the makeup and function of living organisms. They include carbohydrates, lipids, proteins, and nucleic acids. Each class of these molecules serves distinct functions in the cell: carbohydrates provide energy and structural support, proteins perform a vast array of functions including catalysis of biochemical reactions, structural roles, and signaling, while nucleic acids, like DNA and RNA, store and transfer genetic information.

Lipids, particularly fats, are biomolecules that provide long-term energy storage and insulation, being critical to life. The ester linkage that characterizes fats within the lipid class of biomolecules is significant due to its role in energy storage, hormonal regulation, and cell membrane integrity, further underlining the interconnect links between all the biomolecules within living systems.