Biosynthesis of cholesterol- a quick revision

Biosynthesis of cholesterol The biosynthesis of cholesterol may be divided into five steps: (1) Synthesis of Mevalonate from acetyl-CoA. (2) Formation of Isoprenoid units from Mevalonate by loss of CO2. (3) Condensation of six isoprenoid units forms Squalene. (4) The cyclization of Squalene gives rise to the parent steroid, Lanosterol. (5)Formation of cholesterol from lanosterol.

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The reaction catalyzed by HMG Co-A Reductase

Case Details A 40-year-old man presents with chest pain that radiates to his left jaw and shoulder. He is diagnosed with a myocardial infarct (heart attack) and is prescribed statin medication. Statins are competitive inhibitors of HMG CoA reductase, which converts HMG Co A to which of the following? Isopentenyl pyrophosphate Mevalonate Geranyl pyrophosphate Farnesyl

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Steps of de novo synthesis of cholesterol

Steps of de novo synthesis of cholesterol Cholesterol is derived from diet, de novo synthesis, and the hydrolysis of cholesteryl esters. A little more than half the cholesterol in the body arises by synthesis (about 700 mg/d), and the average diet provides the remainder. The liver and intestine account for approximately 10% each of the

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Structure and functions of cholesterol

Structure and functions of cholesterol Cholesterol is the major sterol in the animal tissues. The structure of cholesterol consists of four fused rings (the rings in steroids are denoted by the letters A, B, C, and D), with the carbons numbered in the sequence, and an eight numbered, and branched hydrocarbon chain attached to the

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Image challenge 3

Case details The peripheral blood film (figure) of a strict vegetarian suffering from generalized weakness, easy fatigue, sore tongue, and foot drop has been displayed. What might be the diagnosis? Case details Most probably, the patient is suffering from megaloblastic anemia due to cobalamine deficiency. The cause for this anemia is a strict vegetarian dietary

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Starvation induced metabolic alterations

 A 23 –year- old female was brought for consultation by her mother, who was troubled by her daughter’s continuous fatigue, dizziness, and loss of weight. The patient was 6 feet 2 inches tall and weighed 100 pounds. Further questioning revealed that the young woman had been virtually fasting for four months, hoping to obtain a

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Question of the week

Case details A 54- year-old man with Type 1 diabetes is referred to an ophthalmologist for evaluation of developing cataracts. Blood chemistry results are shown below: Fasting blood glucose   198 mg/dl Hemoglobin A                  15 gm/dl Hemoglobin A1c             10% of total Hb Urine ketones                   Positive Urine glucose                    Positive Which of the following enzymes is most strongly

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Molecular Biology- Viva Questions- Set -1

1-State Chargaff’s rule In DNA molecules, the concentration of deoxyadenosine (A) nucleotides equals that of thymidine (T) nucleotides (A = T), while the concentration of deoxyguanosine (G) nucleotides equals that of deoxycytidine (C) nucleotides (G = C). 2- What is meant by hyperchromicity of denaturation?  The conjugated double bonds of purine and pyrimidine derivatives absorb

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