Did you know???

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Hey guys so I am wrapping up on my Biochemistry blog posts. Today I learnt that cholesterol can actually be beneficial to us humans although we think of it as having this negative impact on our lives. It is a compound of the sterol type, C27H45OH, found in most body tissues and important in metabolism.  It’s structural components is composed of:

  • 4 fused ring collectively referred to as the steroid nucleus
  • An OH group on C3 (hydrophilic polar head)
  • An alkyl side chain located on C17
  • 2 methyl groups on C10 and C13
  • A double bond present between C5 anC6
  • Ring D as seen on the picture above is the only 5 membered ring while the other 3 rings are composed of 6 members

The human body contains about 100 g of cholesterol. Most of this is incorporated in the membranes from which cells are constructed and is an indispensable component of them. The insulating layers of myelin wound around neurons are especially rich in cholesterol.

Other uses of cholesterol include the synthesis of the steroid hormones: progesterone, estrogens, androgens (e.g., testosterone), glucocorticoids (e.g., cortisol) and mineralocorticoids (e.g., aldosterone).

Cholesterol is also the precursor from which the body synthesizes vitamin D.

One of the major uses of cholesterol is the synthesis of bile acids. These are synthesized in the liver from cholesterol and are secreted in the bile. They are essential for the absorption of fat from the contents of the intestine. The liver synthesizes some 1500–2000 mg of new cholesterol each day. It synthesizes cholesterol from the products of fat metabolism.

Cholesterol is seen to be beneficial to the human body. It also has negative impacts on the human body. The health effects of cholesterol problems are due to a condition called atherosclerosis, which is narrowing and hardening of arteries. When  levels of cholesterol are too high, LDLs (low density lipoproteins) will leave extra cholesterol in the blood. If the HDLs (high density lipoproteins) cannot pick up all of this cholesterol it will begin to build up on your artery walls along with other fats and debris. This buildup of cholesterol is called plaque. Over time, plaque can cause narrowing of the arteries or atherosclerosis. Health effects of this process include:

  • High blood pressure – increases over 140/190
  • Heart attack- occurs when the supplyof blood and oxygen to part of the heart is blocked
  • Stroke – it is a sudden occurrence where a blood vessel in the brain gets blocked or ruptures
  • Agina – occurs when the heart is not getting enough oxygen-rich blood for a short time

I hoped you have learnt something that is beneficial in understanding this lipid molecule. Until next time…

References:

http://users.rcn.com/jkimball.ma.ultranet/BiologyPages/C/Cholesterol.html

http://cholesterol.emedtv.com/high-cholesterol/health-effects-of-cholesterol.html

g v b

fatty_acids

Unsaturated Fats:

characteristics include:

  • at least one carbon-carbon double bond

  • liquid at room temperature

  • kinks created which prevents packing

  • contain cis double bonds

  • monounsturated chain contains only one double bond eg. oleic acid

  • polyunsaturated fats contain more than one double bond eg. linoleic acid

  • sources are plants and fish fats

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lin

Saturated Fats:

characteristics include:

  • no carbon-carbon double bond

  • solid at room temperature

  • no kinks created so there is tightly packing

  • long, straight chains

  • eg. stearic acid and palmitic acid

  • sources are from animal fats

 

satu

Trans Fats:

It seemed like such a good thing once since it enhances the flavor, texture and shelf life of many processed foods. However, it comes with a health risk. Trans fatty foods tantalize a persons taste buds then travel through your digestive system to your arteries where they turn to sludge.

Small amounts of trans fats occur naturally in beef, lamb and full-fat dairy products. Most come from processing liquid vegetable oil to become a solid fat through a process called hydrogenation. 

trans-fats-111111c-02

References:

http://www.myhealthnewsdaily.com/1902-the-truth-about-trans-fats.html

http://lpi.oregonstate.edu/f-w98/primer.html

http://telstar.ote.cmu.edu/biology/MembranePage/index2.html

http://www.raw-milk-facts.com/fatty_acids_T3.html

http://www.emeraldinsight.com/journals.htm?articleid=866412&show=html