To get the best deal on Tutoring, call 1-855-666-7440 (Toll Free)
Top

Cholesterol Structure

Steroids are a group of compounds which are soluble in organic fat solvents but cannot be hydrolyzed by NaOH. Steroids containing alcoholic group at C -3 positions and a side chain of 8 to 10 carbon atoms at C-17 are called sterols.

Cholesterol is the best example of sterols. The name cholesterol originates from the Greek word chole- and stereos, and the
suffix for alcoholic group It is most abundant in brain, nerves, and adrenals and in skin. It is prepared by liver. It helps in formation of different hormones. But it is absent in prokaryotic cells.It is an important component for bile juice formation.

Structure of Cholesterol

 

Chemical Structure of Cholesterol

Back to Top

Its molecular formula is C27H46O. Cholesterol contains steroid rings with a hydroxyl group, two methyl groups and a hydrogen tail. It is found in all plants and animals. Cholesterol is essential for all animal life, cholesterol is necessary for building and maintenance of membranes. It helps to regulates membrane fluidity over the range of physiological temperatures. So if the balance is not being maintained inside the body one may suffer.

Cholesterol Structure

Chemical Structure of Cholesterol

The relative abundance of pure cholesterol and bile acids focused early research aimed at unraveling the chemical structure of steroids on those two compounds. The investigations aimed at elucidating the structure of cholesterol and cholic acid was probably undertaken largely as an exercise in structural organic chemistry.

Function of Cholesterol

Back to Top

Cholesterol is essential for all animal life, cholesterol is necessary for building and maintenance of membranes. Other sites of high synthesis rates include the intestines, adrenal glands, and reproductive organs. It helps to regulates membrane fluidity over the range of physiological temperatures.

Cholesterol also functions in intracellular transport, cell signaling and nerve conduction. Human breast milk also contains significant quantities of cholesterol.

  1. High level of cholesterol: Cholesterol is very important for all animals but a high level of serum cholesterol may lead to heart disease. Cholesterol is prepare in the body by liver. It helps in preparation of certain adrenal hormones.
  2. Low level of cholesterol: If the cholesterol level inside our body becomes low, then we might suffer from depression, anxiety and even lead to a case of suicide.

Steroids containing alcoholic group at C-3 positions and a side chain of 8 to 10 carbon atoms at C-17 are called sterols. Cholesterol is the best example of sterols. It is most abundant in brain, nerves, and adrenals and in skin. It is prepared by liver. It helps in formation of different hormones. But it is absent in prokaryotic cells. It is an important component for bile juice formation. Cholesterol is necessary for building and maintenance of membranes.

Cholesterol Synthesis

Back to Top
Cholesterol synthesis requires acetyl CoA, ATP, NADPH and O2. The overall reaction is described by the following equation.

18Acetyl CoA + 18ATP + 16NADPH + 4O2 Clolesterol + 9CO2 + 16NADP + 18ADP + 18P

The pathway can be described in four stages.
  1. The first stage is the formation of HMG CoA by the sequential condensation of three molecules of acetyl CoA.
  2. The second stage is the conversion of HMG CoA to two types of activated isoprenoids, is Isopentyl pyrophosphate and dimethylallyl pyrophosphate. The synthesis of each isoprenoid requires three molecules of ATP. These C5 compounds readily polymerize and are used as building blocks in several synthetic pathways.
  3. The third stage is the condensation of six isoprenoids to form squakence, a process that involves C10 and C15 intermediates.
  4. The fourth stage is the conversion of squalence a linear C30 compound, to cholesterol, a cyclic C27 compound. Lanosterol is the first intermediate with a steroid nucleus.
Related Topics
Chemistry Help Chemistry Tutor
*AP and SAT are registered trademarks of the College Board.