Question

ALL lipids are:

a) Soluble in water
b) Insoluble in water
c) contain a fatty acid
d) cholesterol

Answer 1

Lipids are insoluble in water due to their non-polar nature and are freely soluble in organic solvents. The lipid category includes a variety of compounds, such as fats and cholesterol, the latter of which is classified as a steroid.

Step-by-step explanation:

All lipids are insoluble in water because they are hydrophobic and are composed of non-polar molecules. This distinct characteristic arises from their non-polar carbon-carbon or carbon-hydrogen bonds, making them unable to form true solutions in water. Instead, they may form emulsions, which are mixtures of two solutions that don't mix evenly. Moreover, lipids are a broad category that includes fats, waxes, phospholipids, steroids like cholesterol, and fat-soluble vitamins, among others. Each of these compounds shares the common feature of being water-insoluble but is freely soluble in organic solvents such as ether and benzene. Fats that are solid at room temperature and obtained from animal sources, known as saturated fats, are characterized by having only single bonds within their carbon chain and are also insoluble in water. Cholesterol is specifically classified within the lipid category as a steroid, which is just one type of lipid.

Answer 2

b) Insoluble in water

Step-by-step explanation:

Lipids or fats are water-insoluble organic molecules and soluble in certain organic substances such as alcohol, ether and acetone.

Lipids can be found in plant and animal foods and should be consumed in a balanced manner. These molecules have functions such as energy reserve, thermal insulation and vitamin absorption.

Lipids are esters, meaning they are composed of one acid molecule (fatty acid) and one alcohol molecule (glycerol or other). They are insoluble in water because their molecules are nonpolar, that is, they have no electric charge and therefore have no affinity for the polar molecules of water.