Lipids Flashcards
Lipids are classified according to what?
Their functions
What is the solubility of Lipids?
Lipids are insoluble in water but soluble in nonpolar solvents (eg. hexane, ether, benzene). *Acetone (polar) can dissolve polar lipids.
Storage lipids are also called?
Neutral Lipids
These are esters of glycerol and fatty acids.
Triglycerides/Triacylglycerols (TAGs)
These are storage forms of fatty acids in animals and humans in adipose tissue.
Triglycerides/Triacylglycerols (TAGs)
Examples of Triglycerides
Fats and Fixed oils
Fats are (solid/liquid) at room temp?
Solid
The only fat that is a liquid at room temp.
Cod liver oil
Fixed oils are (solid/liquid) at room temp?
Liquid
The only solid fixed oil at rm temp.
Theobroma oil
Saturated fatty acid with 2 carbon atoms
Acetic acid
Saturated fatty acid with 4 carbon atoms
Butyric acid
Saturated fatty acid with 6 carbon atoms
Caproic acid
Saturated fatty acid with 8 carbon atoms
Caprylic acid
Saturated fatty acid with 10 carbon atoms
Capric acid
Saturated fatty acid with 12 carbon atoms
Lauric acid
Saturated fatty acid with 14 carbon atoms
Myristic acid
Saturated fatty acid with 16 carbon atoms
Palmitic acid
Saturated fatty acid with 18 carbon atoms
Stearic acid
Saturated fatty acid with 20 carbon atoms
Arachidic acid
Most abundant saturated fatty acid in animals and humans
Palmitic acid
What is the meaning of a ‘saturated’ compound?
It has no multiple bonds.
What is the meaning of an ‘unsaturated’ compound?
It has multiple bonds.
Describe structure of monounsaturated fatty acids and give examples.
They have 1 double bond. Examples are palmitoleic acid and oleic acid.
How many carbon atoms does palmitoleic acid have? Where is its double bond found?
16 Carbon atoms, double bond between C9 and C10.
How many carbon atoms does oleic acid have? Where is its double bond found?
18 carbon atoms, double bond at 9-10
Polyunsaturated fatty acids are also known as?
Essential fatty acids
Enumerate the three essential fatty acids.
Linoleic acid, Linolenic acid, and Arachidonic acid
What is the conditionally essential fatty acid? Why is it only ‘conditionally’?
Arachidonic acid. We can synthesize it but its precursor are essential fatty acids (Linoleic and Linolenic acid).
Linoleic acid is commonly known as?
Omega-6
Linolenic acid is commonly known as?
Omega-3
What are the 4 different types of lipids according to function?
Triglycerides/Triacylglycerols (TAGs)
Structural Lipids
Terpenoids
Eicosanoids
What are the 3 different fatty acid components of TAGs?
Saturated fatty acids
Monounsaturated fatty acids
Polyunsaturated fatty acids
What are the 2 types of Structural/Natural Lipids?
Triglycerides/Triacylglycerides
Waxes
What is the structure of waxes?
Waxes are esters of fatty acids with high MW monohydric alcohols.
Give examples of waxes.
Beeswax, Lanolin, Carnauba wax, Spermaceti
What is the main function of Structural Lipids?
They are major components of the cell membrane.
What are the three types of Structural Lipids?
Phosphoglycerides, Sphingolipids, and Sterols
What are the functional groups of Phosphoglycerides?
Phosphoglycerides are esters of glycerol, fatty acids, phosphates, and a polar head group.
Which of the functional groups of Structural lipids varies?
The polar head group
What is the parent compound of Phosphoglycerides?
Phosphatidic acid with -H as polar head.
What is the phosphoglyceride with a polar head of choline?
Phosphatidyl choline
What is the phosphoglyceride with a polar head of ethanolomine?
Ethanolamine
What is the phosphoglyceride with a polar head of serine?
Phosphatidyl serine
Phosphatidyl choline is more commonly known as?
Lecithin
Phosphatidyl ethanolamine is more commonly known as?
Cephalin
What phosphoglycerides have degradation products that are precursors for 2° messengers?
Phosphatidyl inositol
What phosphoglyceride is an important component of cardiolipin?
Phosphatidyl glycerol
What are the functional groups of Sphingolipids?
Sphingosine (an alcohol)
Fatty acid
Polar head group
This is the parent of Sphingolipids in relation to structures.
Ceramide
What is a ceramide?
Ceramide is the amide of sphingosine and fatty acid.
Ceramide + phosphocoline/phosphoethanolamine
Sphingomyelins
Sphingomyelins are found where?
Myelin sheath
Ceramide + monosaccharide
Cerebrosides
Ceramide + disaccharide or neutral oligosaccharide
Globosides
Ceramide + charged oligosaccharide
Gangliosides (-)
The charged oligosaccharide in gangliosides (-) that gives its (-) charge.
N-acetylneuraminic acid
N-acetylneuraminic acid is commonly known as?
Sialic acid
What is the charge of cerebrosides and globosides?
Neutral
Cholesterols are classified as?
Sterols (under Structural Lipids)
What is the function of cholesterol in the cell membrane?
It controls the rigidity and fluidity.
Cholesterol can be found in plants. True/False.
False
Cholesterol is a precursor in the synthesis of what?
Steroid hormones and Bile acids
Where are bile acids produced? stored?
Bile acids are produced in the liver and stored in the gall bladder.
Main function of bile acids.
Fat emusification and digestion
Give examples of bile acids derived from cholesterol.
Cholic acid
Deoxycholic acid
Lithocholic acid
Chenodeoxycholic acid
What are the transport forms of cholesterol in the body?
Lipoproteins
What are the bad cholesterol and good cholesterol?
LDL - bad cholesterol
HDL - good cholesterol
This type of lipoprotein is transported to peripheral tissues.
LDL
This type of lipoprotein is transported into the liver for metabolism.
HDL
These are sterols found in plants.
Sitosterol, Stigmasterol
This sterol is found in the cell walls of fungi.
Ergosterol
Main structure of steroids
(CPPP) cyclopentanoperhydrophenanthrene
This type of lipids are polymers of isoprene unit.
Terpenoids
Example of Terpenoids
Fat soluble vitamins
Fat soluble vitamins
Vitamins A, D, E, K
Function of vitamin A
Antioxidant
Vitamin E is an anti-aging vitamin because it prevents what?
Lipid peroxidation
Function of vitamin K
Blood clotting
Eicosanoids are derived from?
Arachidonic acid
Eicosanoids that are mediators of pain, fever, and inflammation
Prostaglandins
Leukotrienes
Thromboxanes
Thromboxane responsible for platelet aggregation
TXA2