Lipids Bio Molecule Quiz Questions

Lipids are insoluble in water because they are hydrophobic molecules. They have a nonpolar structure, which means they do not have a charge and cannot form hydrogen bonds with water molecules. Instead, lipids tend to aggregate together and form separate phases in water, such as oil droplets. This lack of solubility in water is why lipids are commonly found in cell membranes and used as energy storage molecules in organisms.

Fats and oils are composed of molecules called triglycerides. Triglycerides are a type of lipid, which are organic compounds that are insoluble in water. They are made up of three fatty acid molecules attached to a glycerol molecule. Fats and oils serve as a concentrated source of energy in the body and also play important roles in insulation, protection of organs, and absorption of fat-soluble vitamins.

Saturated fatty acids have higher melting points than unsaturated fatty acids because they have straight chains and can pack tightly together. This strong packing leads to stronger intermolecular forces, making it more difficult for the molecules to break apart and melt. In contrast, unsaturated fatty acids have kinks in their chains due to double bonds, which disrupt the packing and weaken the intermolecular forces, resulting in lower melting points.

Cholesterol is classified as a steroid. Steroids are a type of organic compound that have a specific structure known as a steroid nucleus. Cholesterol fits this structure, as it contains the characteristic four fused rings of carbon atoms. Steroids are important in the body as they serve as precursors for various hormones and are involved in several physiological processes. Cholesterol, specifically, plays a crucial role in the formation of cell membranes and the production of certain hormones, such as estrogen and testosterone.

Three fatty acids join on to a glycerol molecule by a condensation reaction. The bonds formed are called ester bonds.