Lipids Flashcards
What are lipids?
characterized by insolubility in water and solubility in nonpolar organic solvents
What is the structure of phospholipids?
a phosphate and alcohol that comprise the polar head group, joined to a hydrophobic fatty acid tail by phosphodiester linkages
What does fully saturated mean?
mean the chain only has single bonds - so saturated with hydrogens
What are glycerophospholipids?
phospholipids that contain a glycerol backbone bonded by ester linkages to two fatty acids and a by a phosphodiester linkage to a highly polar head group
What are sphinoglipids?
have a sphingosine backbone and long-chain, nonpolar fatty acid tails and polar head group s
What is a ceramide?
a sphingolipid with a single hydrogen atom as its head group
What are sphingomyelins?
major class of sphingolipids that are also phospholipids; have either phosphatydylcholine or phosphatidylethanolamine as head group and contain a phosphodiester bond; not net charge on head groups
What are glycosphingolipids?
sphingolipids with head group composed of sugars bonded by glycosidic linkages; not phospholipids (lack phosphodiester linkage)
What are cerebrosides?
glycosphinoglipids with a single sugar
What are globosides?
glycosphingolipids with two or more sugars
What are gangliosides?
glycolipids that have polar head groups composed of oligosaccharides with one or more n-acetylneuraminic acid (NANA)
What are waxes?
esters of long-chain fatty acids with long-chain alcohols
What are terpenes?
a class of lipids built from isoprene moieties and share a common structural pattern with carbon grouped in multiples of five; mainly produced by plants and insects
How many isoprenes are in a terpene?
two
What are steriods?
characterized by having four cycloalkane rings fused together: three cyclohexane and one cyclopentane; nonpolar
What are steroid hormones?
steroids that act as hormones; they are secreted by endocrine glands and travel on protein carriers to distant sites and bind to specific high-affinity receptors and alter gene expression levels
What is cholesterol?
major component of the phospholipid bilayer and is responsible for mediating membrane fluidity; amphipathic
What are prostaglandins?
20-carbon molecules are unsaturated carboxylic acid derived from arachidonic acid and contain one-five carbon ring; act as paracrine and autocrine signaling molecules
What is the biological function of prostaglandins?
regulate the synthesis of cyclic adenosine monophosphate (cAMP)
What is a vitamin?
essential nutrient that cannot be adequately synthesized and must be consumed; water and lipid soluble
What is vitamin A?
carotene; unsaturated hydrocarbon that is important in vision, growth and development, and immune function
What is vitamin D?
cholecaliciferol; consumed or formed in a UV light-driven reaction in the skin; increases calcium and phosphate uptake in the intestines, which promote bone growth
What are rickets?
a condition seen in children and characterized by underdeveloped, curved long bones as well as impeded growth caused by lack of Vitamin D
What is vitamin E?
tocopherols and tocotrienols; characterized by a substituted aromatic ring with a long isoprenoid side chain and are characterstically hydrophobic; antioxidants
What is vitamin K?
a group of compounds, including phylloquinone and menaquinones; critical to posttranslational modifications required to form prothrombin, important clotting factor in the blood
What is a triacylglycerol?
three fatty acids bonded by ester linkages to glycerol; nonpolar and hydrophobic
What is saponification?
the ester hydrolysis of triacylglycerols using a strong base
What is lye?
sodium or potassium hydroxide
