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Is Cholesterol Polar or Non-Polar

Cholesterol (C22H46O) is an organic molecule that belongs to the steroid family. It can be found in body tissues such as the liver, brain, spinal cord as well as in the blood plasma.

This waxy substance is extremely important in order for the body to carry out several functions such as producing steroid hormones (testosterone, estrogen, and progesterone), vitamin D, and other compounds from which the body synthesizes bile acids.

Moreover, cholesterol plays a huge role in brain synapses and in the immune system. 

In terms of polarity, determining whether a molecule is polar or non-polar is important in order to find out whether said molecule is attracted or repelled to water.

Molecules with high polarity are hydrophilic also called water-loving, whereas molecules with low polarity are hydrophobic, also known as water-fearing.

Now here comes the big question, is cholesterol polar or non-polar? Keep on reading to find it out.

Is Cholesterol Polar or Non-Polar

Is Cholesterol Polar or Non-Polar – Cholesterol Structure

Cholesterol is essential for human physiology and cell functions. In the plasma membrane, for example, cholesterol plays a huge role by contributing to its functionality, fluidity, and permeability.

In terms of structure, cholesterol is a steroid based on a cholestane skeleton. It has a double bond at the 5,6 position and a 3beta-hydroxy group. This lipid molecule is composed mostly of carbon and hydrogen. Unlike fatty acids, cholesterol is arranged in a series of rings, this structure turns cholesterol into a quite rigid substance, except for the somewhat flexible tail.

As for the production, cholesterol is synthesized in the liver’s cells by a multistep process that takes place in the cytoplasm and the reticulum endoplasmatic of the cell. 

Regarding polarity, cholesterol is a non-polar molecule, in other words, it is generally repelled to water, however, there is a hydroxyl group attached to cholesterol’s first ring that turns this specific cholesterol part attracted to water.

This characteristic of cholesterol is especially relevant to the cell membrane functionality. Cholesterol has the ability to insert itself between the phospholipids that composes the membrane bilayer, preventing the diffusion across the membrane of water-soluble molecules.

The cholesterol’s hydroxyl group sticks into the water surroundings (intra or extra cellular water), while the non-polar part is found between the phospholipid tails.

In addition, cholesterol has the capacity to affect membrane fluidity by increasing the temperature range in which the plasma membrane can continue to function.=

Are Lipids Polar or Non-Polar

Lipids can be classified into three major groups, phospholipids, steroids, and triglycerides. Below you will find a brief explanation of each one of these:

Phospholipids: They are made of two fatty acids and a phosphate group. Phospholipids are present in the cell membrane of every living animal and they basically provide a structural function to the cell membrane.

Steroid: Cholesterol is a type of steroid, this substance is used in the body to synthesize hormones such as testosterone, estrogen, and progesterone. It is also an important component of the cell membrane, it provides it with permeability and fluidity.

Triglycerides: Triglycerides are constructed with three fatty acids molecules and one glycerol molecule.

Contrary to what people tend to think, triglycerides are formed when there is an excess of glucose in the body, yes glucose and not fat, these molecules travel to the adipocyte tissue in order to be stored, increasing people’s fat body percentages.

In addition, lipids have a distinctive ability to perform many different functions in a cell. The large majority of lipids are non-polar with only a few of them being slightly polar and having a few charged areas.

Have you ever tried to mix oil and water together? If not, try this experiment at your home. You will see that oil and water do not mix together, they form two separate layers, water will sink to the bottom while oil will be on top.

This happens because lipids are non-polar molecule and water on the other hand water is a polar molecule. 

By now you might be wondering, but why is this? Water is a polar  molecule because the negatively charged electrons that rotate around the nuclei of the atom are not regularly distributed.

On the contrary, lipids are non-polar, meaning that their charge distribution is even. For this reason, non-polar molecules such as lipids do not dissolve well in polar molecules such as water.

Are Carbohydrates Polar or Non-Polar?

What about carbohydrates, are they polar or non-polar? Contrary to lipids, all carbohydrates are polar. Try to carry out this experiment at home, mix one tablespoon of sugar in a cup filled with water. After doing that, you will see that the opposite of what happened with the oil experiment will occur, sugar can fully combine with water.

Is Cholesterol Polar or Non-Polar Conclusion

Polar and non-polar is the main characteristic in order to distinguish molecules from each other. This characteristic is especially relevant in biological chemistry because it determines whether molecules will interact or not with each other.

In a few words, polarity makes reference to the electric charge distribution around the molecule. Polar molecules present an electronegativity difference between bonded atoms, while on the contrary, non-polar molecules present an even distribution between atoms. 

The most remarkable example of a polar molecule is water, ethanol and ammonia are also other examples of polar substances. 

On the other hand, cholesterol is a non-polar molecule, meaning that its electrons are evenly distributed. 

Other examples of non-polar molecules include most organic substances, carbon dioxide, and methane. 

To sum up, if you want to know if two substances are able to mix, check for their polarity. If they share the same polarity they will mix, however, if they have different polarity, they will not mix.


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