Nplex Biochem Lipids

Biochemistry ~ Lipids

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during fasting  fatty acids (from adipose triglyceride stores) are oxidized by various tissues to produce energy

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in the liver, fatty acids are converted to ketone bodies  oxidized by tissues such as muscle and kidney

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lipids are a heterogenous group of water-insoluble, organic molecules they can be extracted from tissues by nonpolar solvents most important storage form of chemical energy in the body (mostly as long chain triglycerides)

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fatty acids (hydrophobic) are used to make triglycerides – storage form or fats

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fatty acids are the amphipathic (part of molecule is hydrophilic, part of molecule is hydrophobic) molecules that the adipocyte releases when we are fasting adipocyte breaks its triglycerides down and releases fatty acids and glycerol trigylcerides are composed of glycerol (water soluble) and three fatty acids (not very water soluble) fatty acids are not very water soluble but they can bind to albumin an albumin molecule can bind two fatty acids and can thus transport them to various tissues where they are used as very good fuels

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A.) Types

1. Fatty Acids (saturated, unsaturated, essential, nonessential, short chain, medium chain, long chain, cis, trans)

fats are the major source of energy in the liver and muscle, and in all human tissues in general  except the red blood cells and the brain fats are not water soluble enzymes that break them down are soluble fats are important components of all cells and tissues membranes have lipids (esp. phosphoglycerides, sphingolipids & cholesterol) in adipose cells, fatty acids are converted to triglycerides & stored

Structure: - building block components of most lipids - long chain organic acids having from 4-24 carbon atoms made up of a singly carboxyl group and a long, non-polar hydrocarbon “tail” - in humans they usually have an even number of carbons and are 16-20 carbon atoms in length - may be saturated, or unsaturated (contain double bonds) - 20:4 = 2 carbon FA with 4 double bonds - can exist in free form or esterfied to a glycerol Degree of saturation: - defined by the number of double bonds between the carbon atoms in the chain a.) Saturated Fatty Acids: - saturated fatty acids have all carbon molecules bound separately to either H or another C - NO double bonds - solid at room temperature Sources: - butter, animal fat, fish oil, coconut oil, cottonseed oil b.) Unsaturated Fatty Acids: - contain a carbon-carbon double bond - occur naturally in cis form - liquid at room temperature Sources: - monounsaturated  one double bond  in olive oil, canola oil, & avocados - polyunsaturated  safflower oil, flax see oil, walnuts, evening primrose oil, animal fat, cold water fish, and cod liver oil c.) Essential Fatty Acids: - gamma linoleic and alpha-linolenic = polyunsaturated fats that the human body cannot manufacture - All other FA’s are non-essential - humans requires EFA in the diet to make eicosanoic FAs (prostaglandins, thromboxanes etc…) Sources: - linoleic acid from  evening primrose (best source), nuts, seeds, grains, & legumes - alpha-linoleic acid  flax, candlenut, hemp, pumpkin, soy, walnut & rape seeds d.) Short Chain Fatty Acids (SCFA’s) - relatively simple organic compounds composed of only 2-6 carbon atoms

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