Questions to study.
1. Ketone bodies: their representatives and significance. Synthesis of ke-tone bodies in the liver and its regulation. Catabolism of ketone bodies in extrahepatic tissues.
2. Structure and biological significance of cholesterol. Biosynthesis of cholesterol. Catabolism of cholesterol.
3. Phospholipids: their classification, representatives, biological significance. Metabolism of phospholipids.
4. Sphingolipids: their classification, representatives and metabolism.
5. Regulation of lipid metabolism.
6. Abnormality of lipid metabolism. Obesity and atherosclerosis.
Assignment for self-instruction
| | Guidelines for performing the task |
| Study the pathways of acetyl-C A use in cells and metabolism of ketone bodies | 1. Write down the scheme of pathway of acetyl-CoA use in the cell. 2. Write down chemical formulas of ketone bodies. 3. Write down reactions of synthesis of ketone bodies in the liver and reactions of their breakdown in extrahepatic tissues. What is the biological role of ketone bodies? |
| Study metabolism of cholesterol in tissues | 1. Study the stages of biosynthesis of cholesterol in tissues. Name the key regulatory (rate-limiting) enzyme. 2. Study the features of cholesterol transport in the bloodstream. 3. Write a reaction catalyzed ACAT and LCAT. 4. Write down specific directions of cholesterol metabolism in the skin, liver, sex glands, adrenal cortex |
Ending of the table
| | Guidelines for performing the task |
| | 5. What is the role of cholesterol in development of gallstone disease and atherosclerosis? |
| Study the structure of bile acids and their role in digestion and absorption of lipids | 1. Write down structural formulas of bile acids: cholic, deoxycholic, cheno-deoxycholic, lithocholic acid. 2. What are conjugated bile acids? What is their biological significance? Write down formulas of glycodeoxycholic and taurocholic acid. 3. What is the significance of bile in digestion and absorption of dietary lipids? |
| Study the structure of the main types of complex lipids | 1. Write down structural formulas of glycerophosphatides and sphingolip-ids: phosphatidic acid, phosphatidyl choline, phosphatidyl serine, phospha-tidyl ethanolamine, phosphatidyl inosotol, sphingomyelins, cerebrosides, gangliosides. 2. Make a schematic drawing of the structure of biological membranes and indicate the localization of complex lipids |
| Study metabolism of glycerol-phosphatides | 1. Write down the scheme of stepwise decomposition of phosphatidyl choline in reactions catalized by phospholipases. 2. Write down reactions of synthesis of glycerophosphatides using phos-phatidic acid. 3. Write down reactions of synthesis of phosphotidyl glycerols using diac-ylglycerol and nitrogen-containing alcohols. 4. What is the mechanism of lipotropic effect of choline, inositole and methionine? |
| Study the regulation of lipid metabolism | 1. Characterize the effect of diet on metabolism of TAGs and cholesterol. 2. Name lipogenic and lipolytic hormones. 3. Explain the mechanism of action of epinephrine, norepinephrine, growth hormone, thyroxin, insulin, prostaglandins, sex hormones on lipid metabolism |
Librαry-reseαrchpαper 1. Lysosomal diseases.
LABORATORY WORK 1. Quantification of total phospholipids in the blood
Phospholipids are precipitated with trichloroacetic acid. After dissolving of the resulting precipitate in perchloric acid its content of inorganic phosphorus is determined.
Procedure
► Put 2.8 ml of distilled water into a test tube with 0.2 ml of the blood serum.
► Add 3 ml of 10% trichloroacetic acid solution (first 1.5 ml drop by drop with continuous shaking and the remaining 1.5 ml more quickly).
► Leave the samples for 2 min at room temperature and then centrifuge at 3000 rpm for 5 min.
► Remove the supernatant.
► Mix 1 ml of 50-80% perchloric acid and 1-2 glass beads for uniform boiling with sediment.
► Place the test tube in a boiling water bath for 20-30 min until the mixture becomes colorless. During the first 5 min it is recommended to observe the process, until foam formation is over. Add distilled water to the total volume of 7 ml after cooling the sample.
At the same time, one control and three standard samples are prepared.
Control sample: put 0.8 ml of 50-80% perchloric acid into a test tube and adjust the volume to 7 ml with distilled water.