Functional characteristic of lipids:
- Energy Storage (fat in animals, oil in plants).
- Structural Components of Membranes.
- Active Roles
- Signalling (intracellular and extracellular)
- Enzyme co-factors & Vitamins
Double bonds within fatty acids:
saturated:
Unsaturated
polyunsaturated:
Saturated: No double bonds
Unsaturated: 1 double bond
polysaturated: multiple double bonds
The nomenclature of fatty acids addresses three points of potential variability.
What are they?
- Length
- Presence or absence of double bonds.
- Location of double bonds.
Hydrocarbon tails of fatty acids associate through ______________ interactions and ___ ___ ______ forces
hydrophobic interactions and van der waals forces
Triacylglycerol’s are fatty acid Ester linkages of glycerol. What does the triacylglycerol backbone do to the fatty acid chains?
Ester linkage removes the polar carboxyl group to make a more hydrophobic molecule.
On a gram per gram basis, there is _____ times as much energy in fats than
carbohydrates.
Six times as much energy in fats than carbohydrates.
Difference between low oxidation state and low hydration state in energy storage molecules.
Low oxidation: less oxygenated fuels burn more efficiently; triacylglycerides have a lower oxygenation state than oxygen.
Low hydration: Lipids are hydrophobic with limited interaction with water providing a compact, dehydrated energy storage form.
What is saponification?
-Treatment of fat (triacylglycerol) with a strong base breaks the ester linkages
to release free fatty acids.
Membrane lipids can be classified based on their backbone or by their polar head groups. Name the backbones and polar head groups
Backbones: Glycerol, sphingosine
Polar head groups: phospho, glyco
what is the difference between complex and simple triacylglycerols
Simple: has the same 3 fatty acids
Complex: has 3 different fatty acids
head groups of glycerophospholipids can be positive, negative or neutral charge. T or F?
TRUE@!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
What are sterols?
Sterols are structural membrane lipids. Sterols contain four fused ring steroid nucleus: 3-six carbon rings and a 5-carbon D ring.
what are glycerophospholipids?
Most common lipid found in cell membranes.
What are galactolipids and sulfolipids
Phosphate availability is often limiting to plants. To conserve, some plants use sugar and sulfate polar head groups.
What are sphingolipids?
Sphingolipids are derived from sphingosine. Sphingosine provides a backbone for fatty acids. A popular sphingolipid is ceramide.
The melting temperature of a fatty acid mixture reflects the length and
degree of saturation of the hydrocarbon tails. T or F?
TRUE
The more carbons a fatty acid has the _______ the boiling point
Higher
Double bonds have a greater influence than the length of the tail on
fatty acid associations. T or F?
TRUE
The more double bonds a fatty acid has, the _________ the boiling point
Lower
What are eicosanoids?
-A lipid signaling molecule
three classes of eicosanoids
-Prostaglandins
(constriction of blood vessels)
-Thromboxanes
(involved in blood clot formation)
-Leukotrienes
(smooth-muscle contraction)
What is vitamin D associated with?
-Vitamin D Regulates Ca2+ uptake and deposition.
Where are the Fat soluble vitamis stored?
-A,D,E,K
What is vitamin A associated with?
-Retinal (aldehyde) is a light-sensitive compound with a role in vision.
