Fatty Acid Oxidation and Ketogenesis MCQs

Triacylglycerol (TG), which is a neutral fat, is the most common storage form of lipids. They are esters of trihydric alcohol glycerol and fatty acids. Reference: Harper's illustrated biochemistry 32nd edition page 493

Significance of ω3 Fatty Acid Decrease the risk of Cardiovascular Disease Appear to replace arachidonic acid in platelet membranes Lower the production of thromboxane and tendency of the platelet aggregation Decrease Serum Triglycerides Important for Infant Development Lower the risk of various mental illness (Depression, ADHD) Lower the risk of chronic degenerative diseases such as Cancer, Rheumatoid Arthritis, and Alzheimers Disease . Reference: Harper's 32nd edition, page 239

Docosahexaenoic acid/Cervonic acid (DHA; ω3, 22:6), which is synthesized to a limited extent from α-linolenic acid or obtained directly from fish oils, is present in high concentrations in retina, cerebral cortex, testis, and sperm. DHA is particularly needed for development of the brain and retina and is supplied via the placenta and milk. Patients with retinitis pigmentosa are reported to have low blood levels of DHA. Reference: Harper's 32nd edition, page 239

Amino acid is converted to keto acid by Deamination or transamination. Amino acid is converted to biological amines by Decarboxylation. Examples. Histidine to histamine Tyrosine to tyramine. Tryptophan to tryptamine Serine to ethanolamine Reference: Harper's 32 nd edition, page 320

Test for Ketone Bodies Gerhardt's Ferric Chloride Test: Detect Acetoacetate Rothera's Nitroprusside Test: Detect Acetoacetate and Acetone None of the above tests detect Beta hydroxybutyrate, since it lacks the keto group towards which these tests are directed. Reference: Vasudevan and Sreekumari 8/e p207

Lorenzo oil is used for the treatment of Adrenoleukodystrophy. Zellweger Syndrome, also called cerebrohepatorenal syndrome, occurs in individuals with a rare inherited absence of peroxisomes in all tissues. They accumulate C26-C38 polyenoic acids (VLCFA) in brain tissue and also exhibit a generalized loss of peroxisomal functions. The disease causes severe neurologic symptoms, and most patients die in the first year of life. Refsum disease is a rare neurologic disorder caused by a metabolic defect (absence of enzyme phytanoyl CoA dioxygenase) that results in the accumulation of phytanic acid. Phytanic Acid is found in dairy products and ruminant fat and meat. Reference: Harper's illustrated biochemistry 32 nd edition page 532

Under aerobic conditions, pyruvate is taken up into mitochondria, and after oxidative decarboxylation to acetyl-CoA is oxidized to CO2 by the citric acid cycle Under anaerobic conditions, pyruvate is reduced by the NADH to lactate, catalyzed by lactate Reference: Harper's 32 nd edition, Page no.172

Ans. is 'a' i.e., Gluconic acid [Ref : Internet] Oxidase-peroxidase enzyme system is used to determine glucose in urine & blood. Glucose oxidase enzyme produces hydrogen peroxide & gluconic acid from glucose.Peroxidase catalyses the reaction of H202 with colourless potassium iodide to brown iodide. This produces a colour change, the intensity of which may indicate glucose concentration in some tests(such as Boehringer, Diastix). 279. Glucose is converted to glucuronate by ? a) Oxidation of aldehyde group b) Oxidation of terminal alcohol c) Oxidation of both d) None Correct Answer - B Ans. is 'b' i.e., Oxidation of terminal alcohol [Ref Chatterjee 8th/e p. 29] When aldose sugars are oxidized they may form three different sugar acid, depending upon oxidation of aldehyde group (at C-1) or terminal alcohol group (at C-6).