Question

What are the subunits of a triglyceride? What is the difference between a saturated and an unsaturated fatty acid? What are the functions of fats in the body? (pages \(31-33\) )

Short answer

The subunits of a triglyceride consist of three fatty acid chains attached to a glycerol backbone. Saturated fatty acids have no double bonds between carbon atoms and are solid at room temperature, while unsaturated fatty acids have one or more double bonds, causing kinks in the chains and making them liquid at room temperature. Fats have several functions in the body, including energy storage, insulation and protection, structural components for cell membranes and hormones, carrier of fat-soluble vitamins, and a source of essential fatty acids.

Step-by-step solution

Subunits of a Triglyceride

A triglyceride is a type of lipid (fat) molecule found in the body. It consists of three fatty acid chains attached to a glycerol backbone. The fatty acid chains can be either saturated or unsaturated. The fatty acids and the glycerol molecule make up the subunits of a triglyceride.

Saturated vs Unsaturated Fatty Acids

Fatty acids are chains of carbon and hydrogen atoms. The main difference between saturated and unsaturated fatty acids lies in the presence of double bonds between carbon atoms in their molecular structure. Saturated fatty acids have no double bonds between the carbon atoms - they are saturated with hydrogen atoms. This results in a straight chain that can pack closely together, making them solid at room temperature (e.g., butter and lard). In contrast, unsaturated fatty acids have one or more double bonds between carbon atoms. These double bonds create kinks in the fatty acid chain, preventing them from packing closely together and remaining liquid at room temperature (e.g., vegetable oils).

Functions of Fats in the Body

Fats have several important functions in the body: 1. Energy storage: Fats are an efficient way to store energy, as they provide 9 kcal per gram, which is more than double the energy provided by carbohydrates and proteins. The body can store excess calories as triglycerides in adipose tissue for later use. 2. Insulation and protection: Fats in the form of adipose tissue help insulate the body and reduce heat loss. Moreover, they also provide a protective cushion for internal organs, such as the heart and kidneys. 3. Structural component: Fats are essential components of cell membranes and various hormones, contributing to the integrity and functionality of cells and tissues. 4. Carrier of fat-soluble vitamins: Fats play a vital role in transporting fat-soluble vitamins, namely vitamins A, D, E, and K. These vitamins are essential for maintaining various body functions, such as blood clotting and immune system. 5. Source of essential fatty acids: Fats are the primary source of essential fatty acids, such as omega-3 and omega-6. These fatty acids cannot be produced by the body and must be obtained through the diet. They play critical roles in brain development, inflammation regulation, and cardiovascular health.