Lipid structure and function Flashcards
Structure and Function of Lipids
-Amphipathic: they have both hydrophobic tails and hydrophilic heads, allowing the formation of bilayers in aqueous solutions
Fatty acid tails
structural role and make a bulk of the phospholipid bilayer
polar head
determines functional differences between membrane lipids due to its constant exposure to exterior environment of the phospholipid bilayer
Glycerophospholipids
Phospholipids with glycerol backbone
They have: a polar head, glycerol, and two fatty acid tails
Sphingolipids
Contain a sphingosine or sphingoid
Not all phospholipids
What is the difference between a sphingolipid that is also a phospholipid and one that is not?
- The difference is in the bond between sphingosine backbone and the head group.
- When its a phospholipid it is a phosphodiester bond
- When its a nonphospholipid sphingolipids including glucolipids, they contain a glycosidic linkage to sugar.
What are the three main types of sphingolipids
types of sphingolipids: ceramides, phosphosphingolipids (sphingomyelins), and glycosphingolipids, which differ in the substituents on their head group.Nov 29, 2003
Sphingomyelin
- Phospholipid
- Contains either a phosphatidylethanolamine or phosphatidylcholine
- Component of myelin sheath
Glycosphingolipid
- Glycolipid
- Contains sugars
-Cerebrosides- single sugars
Globosides- two or more sugars - outside of plasma membrane
Ganglioside
- Glycolipid
- Contains oligosaccharides or N-acetylneuraminic acid (NANA)
- most complex
- cell interactions, recognition and single transduction
Waxes
Esters of long-chain fatty acids with long -chain alcohols
- protection for plants and animals (prevent dehydration)
Terpenes
Odiferous steroid precursors made from isoprene (C5H8)
Single terpene unit has 2 isoprene- monoterpene (C10H16)
3 isoprene units
Sesquiterpenes
4 isoprene units
Diterpenes
6 isoprene units
Triterpenes
8 isoprene units
Tetraterpenes
What is the difference between steroid and steroid hormone?
Steroid (derivative of terpenes) defined by its structure: it includes three cyclohexane rings and a cyclopentane ring.
A steroid hormone is a molecule within this class that also functions as a hormone - it travels in the bloodstream, is active at low concentrations, has high-affinity receptors, and affects gene expression and metabolism.
Prodtaglandins
Autocrine and paracrine signaling molecules that regulate cAMP levels which is regulated in many pathways, including those that drive pain and inflammation.
What are the 4 fat soluble vitamins
K, E, A, D
Karen Eat Apples Daily
Vitamin A
Carotene
Vision; metabolized to retinal (aldehyde form) for vision and retinoic acid for gene expression in epithelial development
Vitamin D
Cholecalciferol
Calcium and phosphate regulation and needed for bone formation
Vitamin E
Tocopherols
Biological antioxidants and their aromatic rings destroy free radicals, preventing oxidative damage
hydrophobic
Vitamin K
Phylloquinone and Menaquinones
post-translation modification of prothrombin, addition of calcium -binding sites on many proteins
How does the human body store energy? Why doesn’t it store most of it as sugar
Human body stores spare energy as glycagen and triacylglycerols. Triacylglycerols are preferred because their carbon are more reduced. resulting in a larger amount of energy yield per unit weight. In addition, due to their hydrophobic nature, triacylglycerols do not need to carry extra weight from hydration.
What is the structure and function of triacylglycerols?
Also called triglycerols
- composed of glycerol backbone esterified to three fatty acids. They are used for energy storage
Why does soap appear to dissolve in water?
Soap appears to dissolve in water because amphipathic fatty acid salts form micelles, with hydrophobic fatty acid tails toward the center and carboxylate groups facing outward toward the water. Fat soluble particles can then dissolve inside micelles in the soap water solution and wash away.
Surfactant
lowers the surface tension at the surface of a liquid, serving as detergent or emulsifier.
Sopanification
Ester hydrolysis of triacylglycerols using a strong base to form glycerol and fatty acid salts
