LIPIDS AND ITS METABOLISM

LIPIDS AND ITS METABOLISMLIPIDSCompound that insoluble in water but soluble in polar solvents.Also known as FATS AND OIL .CLASSIFIED INTO TWO GENERAL TYPES FATS AND WAXES ( can be hydrolyzed with ester linkages)CHOLESTEROLS AND STEROIDS ( cannot be hydrolyzed).

SATURATED FATSAnimal oil like meat, milk ,butter.Vegetable oil like coconut and palm kernel oil.POLYUNSATURATED FATSPlan source like safflower , corn, cottonseed, sunflower oil, and soybean oil.MONOUNSATURATED FATPlants and animals product like olive oil, canola oil, avocado and peanut oil.

TYPES OF LIPIDS Excellent energy reservesStucture of cell membrane Body thermal insulationsEssential fatty acids ( EFA)Hormone synthesisFat soluble vitamin absorption FUNCTIONS OF LIPIDS4 LIPID STRUCTURE

LIPIDS DEFICIENCY (Shortage in Lipids intake)LIPIDS EXCEEDING (Overtaking in Lipids intake)

LIPIDS DISORDERSFat should comprise of 3% of total calories to prevent fatty acid deficiencyFatty acid deficiency syndromesDry scaly skin, dermatitis (Linoleic acid deficiency)Hand tremors (Prostaglandin deficiency)Inability to control blood pressure

LIPIDS DEFICIENCYFat should comprise not more than 30% of total calories to prevent lipids exceedingTo prevent overtaking, we should consume fat breakdown (% total calories) 35 mg/dlBLOOD LEVELS OF LIPIDSThe major aspects of lipid metabolism are involved with Fatty Acid Oxidationto produce energy or the synthesis of lipids which is calledLipogenesis. Lipid metabolism is closely connected to the metabolism of carbohydrates which may be converted to fats. This can be seen in the diagram on the left. The metabolism of both is upset by diabetes mellitus.

OVERVIEW IN LIPID METABOLISM

The first step in lipid metabolism is the hydrolysis of the lipid in the cytoplasm to produce glycerol and fatty acids.Since glycerol is a three carbon alcohol, it is metabolized quite readily into an intermediate in glycolysis, dihydroxyacetone phosphate. The last reaction is readily reversible if glycerol is needed for the synthesis of a lipid.The hydroxyacetone, obtained from glycerol is metabolized into one of two possible compounds. Dihydroxyacetone may be converted into pyruvic acid through theglycolysispathway to make energy.

The hydroxyacetone, obtained from glycerol is metabolized into one of two possible compounds. Dihydroxyacetone may be converted into pyruvic acid through theglycolysispathway to make energy.In addition, the dihydroxyacetone may also be used ingluconeogenesisto make glucose-6-phosphate for glucose to the blood or glycogen depending upon what is required at that time.

Fatty acids are oxidized to acetyl CoA in the mitochondria using thefatty acid spiral. The acetyl CoA is then ultimately converted into ATP, CO2, and H2O using thecitric acid cycleand theelectron transport chain.

Fatty acids are synthesized from carbohydrates and occasionally from proteins. Actually, the carbohydrates and proteins have first been catabolized into acetyl CoA. Depending upon the energy requirements, the acetyl CoA enters the citric acid cycle or is used to synthesize fatty acids in a process known as LIPOGENESIS

Plant and animal food contain sterols but only animal food contain cholesterolWhy? Cholesterol is made in the liver and plants do no have a liverCholesterol is needed to make bile, sex hormones, steroids and vitamin D.It is the constituent of cell membrane structureDietary recommendation -