Cholesterol is a lipid that’s either a fat or a fat-like molecule. It is soft and waxy in nature. Cholesterol is a steroid lipid. Steroids are a type of lipid with a unique chemical structure. The structure is composed of four carbon atom rings. Cholesterol is found only in animal cells. The body needs some amount of cholesterol to keep the cell and organs healthy. Animals produce some steroids, which are hormones and cholesterol. Cholesterol is also important in the production of vitamin D and hormones. The discoverer of cholesterol is François Poulletier de la Salle, who identified it in 1769. Cholesterol is not found in prokaryotic organisms, except mycoplasma.

Physiology of cholesterol

Cholesterol is necessary for all animal lives. It is produced by each cell of the animal body. The rate in steps to produce cholesterol. An adult male produces one gram of cholesterol every day. Plants can also reduce cholesterol in very minute quantities; instead of cholesterol, phytosterol is produced by plants. They are chemically similar.

The functions of cholesterol

• 1/3 of the cell membrane of animals is composed of cholesterol. Cholesterol is needed to make and maintain membranes and membrane fluidity.
• It acts as a precursor for the formation of essential compounds for the body, such as the steroid hormones progesterone and testosterone, vitamin D, and bile acids.
• It regulates the biological process of substrate presentation. A substrate presentation is a process to activate proteins.
• Cholesterol is also needed in the process of cell signalling.
• Cholesterol with phospholipid acts as our electrical insulator and functions in the transmission of electrical impulses.
• It serves as a precursor molecule in a number of metabolic processes.

Types of cholesterol

There are 3 types of cholesterol on the basis of its carrier, lipoprotein:

1. Low-density lipoprotein or LDL – It is also known as bad cholesterol. LDL can accumulate on the lining of your arteries, narrowing them. The fatty deposits harden into plaque, which can block your arteries. Atherosclerosis is the name for this build-up. We shouldn’t eat food with LDL cholesterol or saturated or trans-fat.

1. High-density lipoprotein or HDL – It is known as good cholesterol. It’s good because it takes away low-density cholesterol from your arteries. It is like a dumping mechanism that removes bad cholesterol from the body, transfers it to the liver, and reduces the risk of heart disease.

1. Very low-density lipoprotein or VLDL – It transports triglycerides from the intestine and liver to capillary beds in muscle and adipose tissue. It is hydrolysed into fatty acids there and can be oxidised to form adenosine triphosphate (ATP) for energy production.

Conclusion

Cholesterol is a type of lipid. It is basically a steroid that is yellowish waxy and soft in nature that generates cholesterol in the body. The chemical structure of cholesterol is complex. Cholesterol is needed to perform any function of the cell in the animal body. It is not present in plant cells. But high cholesterol levels can cause many diseases because cholesterol builds up in the arteries and blocks the flow of blood, which can cause a heart attack. So it is necessary to maintain cholesterol. We should avoid high cholesterol food for good health. The causes of high cholesterol are smoking, obesity, lack of exercise, and a diet with high saturated fat.