Biochemistry Lipids
17 June 07:16
Lipids are a structuraly assorted chic of biological molecules whose defining backdrop are hydrophobicity and and solubility in amoebic solvents. Lipids accept several roles including activity accumulator and corpuscle signaling and are the above basic of corpuscle mebranes.
A blubbery acerbic is artlessly a beeline carbon alternation with a carboxylic acerbic accumulation at one end:
Fatty acids usually accept amid 14 and 24 carbon atoms and may accept one or added bifold bonds. These bifold bonds are about consistently in the cis configuration.
Fatty acids accept both accepted names and analytical names. The analytical name is based on the alkane or alkene with the aforementioned amount of carbon atoms, with the final e of the hydrocarbon replaced with oic acid. For archetype Laurate (Figure x) is a blubbery acerbic with 12 carbon atoms and no bifold bonds, so the analytical name is dodecanoic acid, and the ionized anatomy is dodecanoate.
(saturated blubbery acerbic table)
If there are bifold bonds, the area is apparent with the attribute Δ with a superscript amount advertence the area of the bifold band and preceded by cis or auto to announce agreement (but about consistently cis). Carbon atoms are counted from the carboxyl end, as in Amount x, so a dodecenoate acerbic with a cis bifold band amid carbon atoms 9 and 10 would be: cis-Δ9-dodecenoate.
The amount 2, 3 and endure carbon atom are alleged the α, β and ω atoms, respectively.
(unsaturated blubbery acerbic table.)
Fatty acids can be affiliated to glycerol to anatomy monoacylglycerols, diacylglycerides and triacylglycerides:
One chic of phospholipids are the phosphoglycerides, which are create from diacylglycerides affiliated to a phosphate group. Phosphoglycerides usually accept the afterward arangement:
There are four accepted phosphate groups. Serine, ethanolamine and choline are structuraly similar, while inositol is different:
Sphingolipids, accept the aforementioned all-embracing appearance as phosphoglycerides but accept altered chemistry, using sphingosine in abode of glycerol. Sphingosine has a continued hydrocarbon appendage agnate to blubbery acids absorbed to a anatomy that is agnate to the amino acerbic serine. A blubbery acerbic can attach to the amine group, and a arch accumulation can attach to a hydroxyl (see Amount x). Sphingolipids are called according to this arch group:
(pictures of ceramide, sphingomyelin, glycosphingolipid)
The majority of sphingolipids are of the third type, glycosphingolipids. It is anticipation they accept functions in corpuscle acceptance and aegis in accession to there structural role in the membrane.
When alloyed in water, phosphoglycerides and sphingolipids will anatomy two chararistics structures. Micelles are spheres constucted from these lipids, with the berserk cape interacting with one addition central the apple and the arctic arch groups interacting with baptize at the apparent of the sphere. These lipids will aswell for whats accepted as a lipid bilayers. These are bedding composed of two layers of lipids area the berserk cape stick into the centermost and the arctic arch groups are on the apparent interacting with water. Corpuscle membranes are composed of lipid bilayers.
(picture of micelle, milcell cantankerous section, lipid bilayer)
A blubbery acerbic is artlessly a beeline carbon alternation with a carboxylic acerbic accumulation at one end:
Fatty acids usually accept amid 14 and 24 carbon atoms and may accept one or added bifold bonds. These bifold bonds are about consistently in the cis configuration.
Fatty acids accept both accepted names and analytical names. The analytical name is based on the alkane or alkene with the aforementioned amount of carbon atoms, with the final e of the hydrocarbon replaced with oic acid. For archetype Laurate (Figure x) is a blubbery acerbic with 12 carbon atoms and no bifold bonds, so the analytical name is dodecanoic acid, and the ionized anatomy is dodecanoate.
(saturated blubbery acerbic table)
If there are bifold bonds, the area is apparent with the attribute Δ with a superscript amount advertence the area of the bifold band and preceded by cis or auto to announce agreement (but about consistently cis). Carbon atoms are counted from the carboxyl end, as in Amount x, so a dodecenoate acerbic with a cis bifold band amid carbon atoms 9 and 10 would be: cis-Δ9-dodecenoate.
The amount 2, 3 and endure carbon atom are alleged the α, β and ω atoms, respectively.
(unsaturated blubbery acerbic table.)
Fatty acids can be affiliated to glycerol to anatomy monoacylglycerols, diacylglycerides and triacylglycerides:
One chic of phospholipids are the phosphoglycerides, which are create from diacylglycerides affiliated to a phosphate group. Phosphoglycerides usually accept the afterward arangement:
There are four accepted phosphate groups. Serine, ethanolamine and choline are structuraly similar, while inositol is different:
Sphingolipids, accept the aforementioned all-embracing appearance as phosphoglycerides but accept altered chemistry, using sphingosine in abode of glycerol. Sphingosine has a continued hydrocarbon appendage agnate to blubbery acids absorbed to a anatomy that is agnate to the amino acerbic serine. A blubbery acerbic can attach to the amine group, and a arch accumulation can attach to a hydroxyl (see Amount x). Sphingolipids are called according to this arch group:
(pictures of ceramide, sphingomyelin, glycosphingolipid)
The majority of sphingolipids are of the third type, glycosphingolipids. It is anticipation they accept functions in corpuscle acceptance and aegis in accession to there structural role in the membrane.
When alloyed in water, phosphoglycerides and sphingolipids will anatomy two chararistics structures. Micelles are spheres constucted from these lipids, with the berserk cape interacting with one addition central the apple and the arctic arch groups interacting with baptize at the apparent of the sphere. These lipids will aswell for whats accepted as a lipid bilayers. These are bedding composed of two layers of lipids area the berserk cape stick into the centermost and the arctic arch groups are on the apparent interacting with water. Corpuscle membranes are composed of lipid bilayers.
(picture of micelle, milcell cantankerous section, lipid bilayer)
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