Question | Answer |
Lipids can be extracted with this | Organic Solvents (CHCl3/ MeOH, 2:1) -2 |
Common Chemical Property of Lipids | Hydrophobicity |
Lipids are biomolecules that partition into the ____ phase | organic solvent |
Function of phospholipids | (permeability barrier) membrane structure |
Function of waxes | waterproof coatings |
function of fat | energy storage |
function of coenzyme Q | electron carrier |
function of steroid hormones and prostalglandins | signal transduction (cell to cell communication) |
function of flavonoids | pigments |
Glycolipids | lipids often linked to sugars (important constituent of cell membrane) |
Lipoproteins | lipids linked to proteins (HDL, LDL) |
lipids have what kind of bond when linked to other classes of biomolecules | covalent |
What are the simplest lipids | Fatty acids |
Fatty acids are... | building blocks of many complex lipids, central intermediates in metabolism |
Triacylglycerols are... | storage fats (derived from fatty acids) |
Phosphoglycerides are... | major lipid component of cell membranes (derived from fatty acids) |
Common fatty acids have how many C atoms? | an even number of C atoms |
What is the trivial name for C-12 | laurate |
What is the trivial name for C-14 | myristate |
What is the trivial name for C-16 | Palmitate |
What is the trivial name for C-18 | Stearate |
What is the trivial name for C-20 | Arachidate |
What do fatty acids do when dispersed in water? | aggregate spontaneously to form roughly spherical micelles |
What are the smallest and simplest lipid aggregates? | Micelles |
The cloudy appearence of soapy water is caused by what? | the scattering of light by micelles |
What formation are double bonds of polyunsaturated fatty acids usually in? | they have double bonds separated by a methylene carbon (they are methylene bridged NOT conjugated) double, single, single, double |
Unsaturated double bonds in naturally occuring fatty acids are usually found in what formation. | Cis form (Trans fatty acids can be made by hydrogenation) |
What effect does saturation have on melt point? | Unsaturation drastically lowers the melt point |
What is used for effective separation of fatty acids? | partition chromatography (esp. gas chromatography) - when combined with mass spec. the mix can be quickly separated, quantitated and identified |
What is gas chromatography? | Molecules are separated based on their partition between a stationary phase and a mobile carrier gas. |
As the column temperature increases _____ is eluted | progressively less volatile compounds (higher molecular weight) compounds are eluted. |
carboxylic acids + alcohols = | ester (condensation)(water taken away) |
carboxylic acids + acids = | acid anhydrides (condensation) |
What is the most important storage form of fatty acids | triacylglycerols |
What is the major constituent of fats and oils | TAGs |
Why are fats and oils so insoluble in water? | because Triacylglycerols (major constituent of fats and oils)have polar carboxylic acids of the fatty acids which are tied up as less polar esters. |
What is the melt point and unsaturation level of animal fat? | high melt point, low unsaturation |
What is the melt point and unsaturation for plant oil? | low melt point, high unsaturation |
What makes fine chocolate melt in your mouth? | Cocoa butter has relatively simple TAG composition that results in unique properties (SOS fats = stearic/ saturated fats that are symmetrical and behave as a single TAG. Lipids of cocoa butter are homogeneous. Cheap chocolates use less expensive fats. |
What is saponification? | hydrolysis of fat with alkali/base (NaOH, lye) to produce glycerol and soap |
TAGs are stored in ___________ | adipose connective tissue. adipose cells are filled with a single large droplet of TAG lipid: the cytoplasm and organelles are squeezed to the periphery. |
Phosphorous is one of the essential elements of life. What is the Chemical formula for phosphoric acid? | H3PO4 (a triprotic acid) -Strong |
What happens during phosphorylation? | Everytime phosphate is added negative charge is added = more polar and more soluble |
Phosphoric acid + alcohol = | phosphate ester + h2o |
Phosphoric acid + acid = | phosphoanhydride + h2o |
How would fatty acids in the lipids of cold water fish differ from warm water fish? | cold water are more unsaturated |
what happens when phospholipids are put in water? | They spontaneously aggregate to form vesicles or liposomes (larger than micelles) |
unilamellar liposome | roughly spherical structure formed by a double layer of phospholipids--it can be considered a sort of protocell (bilayer of membrane surrounding an aqueous compartment) |
this provides a means for delivery of polar, water soluble drugs that would not normally be able to enter a cell | synthetic liposome- (injected intravenously) -can fuse with lipid bilayer of a target cell membrane and thereby deliver its contents into the cell. |
The cellular oxidation of fatty acids is highly___ | exergonic |