Lipids are organic compounds insoluble in water but soluble in organic solvents. Lipids form essential structural component of living cells. Biologically important lipids include fats, phospholipids, and steroids.
|Fats||Fats in human beings are a form of body tissue that serves as a source of energy. It also function as cushion and insulates vital organs. Each gram of fat can produce 9·3 Calories. An enzyme called lipase secreted in the digestive tract, catalyses the breakdown of fats into individual fatty acids before they are absorbed into the bloodstream.|
Fats are made up of two types of molecules namely, glycerol and fatty acids.
Fats are hydrophobic due to the nonpolar nature of C-H bonds in fatty acids.
Fats are divided into 2 main groups, saturated and unsaturated, depending on the proportion of hydrogen atoms.
Fatty acids whose carbon chain cannot absorb any more hydrogen atoms are called saturated fatty acids.
Animal fats are saturated fats. Excessive consumption of these fats is not good for health.
A fatty acid whose carbon chain can absorb additional hydrogen atoms are called unsaturated fatty acids.
Unsaturated Fats are abundant in fish and vegetable oils such as soya, bean, maize, sunflower etc…
Monounsaturated fatty acids(MUFA) are unsaturated fats with only one vacant site in carbon chain that could take an extra hydrogen.
Poly Unsaturated Fatty Acids(PUFA): fatty acid whose carbon chain can absorb relatively high number of additional hydrogen atoms are called polyunsaturated fats.
Essential fatty acids: Essential fatty acids are a form of unsaturated fatty acids, which our body cannot synthesise on its own .
e.g. linoleic acid, linolenic acid, omega-3 fatty acids etc..
Dietary sources: Fatty fish(cod fish), nuts and vegetable oils.
|Diseases caused by fats||
Atherosclerosis: Major cause of heart strokes and high blood pressures.
Cause: excessive consumption of saturated fats.
Formation: fatty deposits inside the arterial walls narrows the arteries and impede the blood flow.
What is body fat?
Fat stored beneath the skin and around various internal organs to serve as a source of energy and provide insulation to vital organs are called body fats or Adipose tissue. Excessive accumulation of adipose tissue as a result of eating more food than is metabolized by exercise and the body’s basic energy needs leads to obesity.
Why fats doesn't mix with water?
Fats separate from water because the hydrogen in water molecules bond with each other and exclude the fats.
What are hydrogenated vegetable oils?
Hydrogenated vegetable oils are unsaturated fatty acids synthetically converted to saturated fats by adding hydrogen to prevent them from becoming rancid.
What are trans-fats?
As a result of hydrogenation, unsaturated fatty acids form trans arrangement of the carbon atoms adjacent to its double bonds. Trans fats contribute more to atherosclerosis(cardiovascular disease) by increasing the ratio of LDL to HDL.