Chem

• Blood Chemistry includes FBS, BUN, CREA, BUA, LIPID PROFILE (CHOLESTEROL, TRIGLYCERIDES, HDL, LDL, VLDL), SERUM LIPIDS, which help in moving and storing energy, absorbing vitamins and making hormones.
• Lipids are insoluble to blood but soluble to organic solvents and are important in the utilization of fat soluble vitamins namely vitamin A, D, E, K.
• Organic solvents are carbon-based substances capable of dissolving or dispersing one or more other substances and can be carcinogens, neurotoxins, reproductive hazards.
• Examples of organic solvents include benzene, toluene, methanol, esters, ethers, acetone, amines, nitrated and halogenated hydrocarbons.
• Fatty acids are building blocks of the fat in our bodies and are linear chains of C-H bonds that terminated with –COOH.
• Fatty acids can be classified as unesterified, bound to albumin, or esterified, which is a constituent of triglycerides or phospholipids.
• Fatty acids can be short (4-6), medium (8-12), or long chain (>12), and can be saturated (no double bonds), mono saturated (single bond), or polyunsaturated (≥double bonds).
• Majority of fatty acids are bound to albumin.
• Ref range for fatty acids is 9-15 mg/dl.
• Triglycerides contain three fatty acids attached to one molecule of glycerol and can contain saturated fatty acids or unsaturated fatty acids.
• Unsaturated fats are liquid at room temperature in oil form.
• Triglycerides contain no charged groups, are water insoluble, and are considered neutral lipids.
• Phospholipids are major membrane lipids that consist of lipid bilayers and act as a barrier to protect the cell against various environmental damage and enable multiple cellular processes to occur in subcellular compartments.
• Phospholipids are derived from phosphatidic acid, which is important in cellular signaling and membrane dynamics in all eukaryotes.
• Phospholipids contain two fatty acids attached to one molecule of glycerol and a phosphate group.
• The third position of phospholipids contain phospholipid head groups.
• Phospholipids are amphipathic, containing hydrophilic head (phosphate and hydrophobic tail (fatty acids), and serve as a surfactant, altering surface tension.
• Four major phospholipids predominate in the plasma membrane of many mammalian cells: phosphatidylcholine, phosphatidylethanolamine, phosphatidylserine, and sphingomyelin.
• Alecithin/phosphatidylcholine is the most abundant phospholipid in the plasma membrane, making up 70% of phospholipids.
• Reference value for cholesterol is less than 200mg/dl, desirable is 200-239 mg/dl, borderline high is 240 mg/dl, and high cholesterol is defined as 240 mg/dl or higher.
• VLDL, or very low density lipoprotein, is also known as pre-beta lipoprotein and is produced in the liver, transferring triglycerides from the liver to peripheral tissue.
• Abnormal amounts of lipids (fatty materials such as waxes, oils, and cholesterol) build up in the brain, spleen, liver, lungs, and bone marrow in Niemann’s Pick disease.
• Unsaturated steroid alcohol cholesterol contains four rings.
• Chylomicrons are the largest and least dense lipoproteins, produced in the intestine, and deliver dietary lipids to hepatic and peripheral cells.
• HDL, or high density lipoprotein, is also known as Alpha lipoprotein or good cholesterol, produced in the liver and the intestine, transferring cholesterol from peripheral cells back to the liver.
• Amphipathic cholesterol contains both hydrophilic and hydrophobic head groups.
• Cholesterol is a waxy substance found in your blood.
• LDL, or low density lipoprotein, is also known as Beta lipoprotein or bad cholesterol, formed from the lipolysis of VLDL to IDL then to LDL, transferring dietary cholesterol to peripheral tissues.
• Lipoprotein lipase (LPL), hepatic lipase, lecithin cholesterol acyl transferase (LCAT), and endothelial lipase are lipolytic enzymes that break down lipoproteins.
• ApoA1 is the most abundant protein in HDL and modulates interactions that affect HDL’s cardioprotective functions, in part via its activation of the enzyme, LCAT.
• Lipoproteins are composed of both lipids and proteins (apolipoproteins) and play a key role in the absorption and transport of dietary lipids by the small intestine, in the transport of lipids from the liver to peripheral tissues, and the transport of lipids from peripheral tissues to the liver and intestine (reverse cholesterol transport).
• Spingomyelin is not derived from glycerol but from sphingosine, a lipid disorder known as Niemann’s Pick disease.
• Both unesterified and esterified cholesterol are bound to fatty acid and LCAT (Lecithin cholesterol acyltransferase) catalyzes the esterification of cholesterol.
• Bile salts are produced from cholesterol and promote fat absorption in the intestine.
• Lipoprotein (a) is a LDL lipoprotein like particle that confers increased risk for premature coronary heart disease and stroke, competing with plasminogen for fibrin.
• Cholesterol is classified as unesterified (amphipathic) or esterified (cholesteryl ester, a neutral lipid that delivers cholesterol and fatty acids to organs).
• Vitamin D and cell membrane are produced from cholesterol.
• Steroid hormones, glucocorticoids, mineralocorticoid, and estrogen, are produced from cholesterol.
• Transport and excretion of cholesterol is promoted by estrogen.
• VLDL stands for very-low-density lipoprotein, a floating lipoprotein found in hyperlipoproteinemia or dysbetalipoproteinemia.