1. A 2-year-old child presents to the clinic with failure to thrive and megaloblastic anemia. Laboratory tests reveal elevated urinary orotic acid levels but normal ammonia levels, normal CSF glutamine levels, and normal serum vitamin B12 and folate levels. Which enzyme deficiency is the most likely cause of this child’s condition? A. Adenosine deaminase B. […]
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1. In adipose tissue, through which of the following intermediates can glucose be converted to glycerol-3-phosphate for the esterification of fatty acids to form triglycerides? A. Acetyl CoA B. Dihydroxyacetone phosphate C. Glycerol D. Malate E. Pyruvate Correct Answer: B. Dihydroxyacetone phosphate: Explanation: Dihydroxyacetone phosphate (DHAP), derived from glycolysis, is reduced to glycerol-3-phosphate by the
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Dear Students, You are invited to take this quiz, which consists of 25 questions designed to test your understanding of the topic. The entire activity will take approximately 40 minutes to complete. Detailed explanations for all questions will be posted later on the website to help you deepen your knowledge. Happy learning, and good luck! Click the link or
Nucleotide metabolism- A Quiz for self-assessment Read More »
Dear students, This 32-question quiz is designed to help you assess your understanding of key concepts in fatty acid and triglyceride metabolism and identify any gaps in your learning. The entire activity is timed for a maximum of 50 minutes, and you are encouraged to complete it in one sitting. You can attempt the quiz
Fatty acid and Triglyceride metabolism- a quiz for self-assessment Read More »
Table 1: Fatty Acid and Triglyceride Metabolism Vitamin Impaired Reaction Enzyme Affected Consequence Riboflavin (B2) β-oxidation of fatty acids Acyl-CoA dehydrogenase Reduced ATP production from fats Niacin (B3) β-oxidation of fatty acids Hydroxyacyl-CoA dehydrogenase Energy generation from fats reduced Triglyceride synthesis Glycerol-3-phosphate dehydrogenase Impaired triglyceride formation Biotin Fatty acid synthesis Acetyl-CoA carboxylase Disrupted synthesis of
Vitamin Impaired Reaction Enzyme Affected Reaction Catalyzed Pathway/Consequence Vitamin B6 (PLP) Transamination of amino acids Aminotransferases (e.g., ALT, AST) Alanine + α-Ketoglutarate ↔ Pyruvate + Glutamate Impaired amino acid catabolism and gluconeogenesis Conversion of glutamate to γ-aminobutyric acid (GABA) Glutamate decarboxylase Glutamate → GABA + CO₂ Impaired neurotransmitter synthesis Conversion of homocysteine to cystathionine
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Vitamin Impaired Reaction Enzyme Affected Reaction Catalyzed Pathway/Consequence Thiamine (B1) Conversion of pyruvate to acetyl-CoA Pyruvate dehydrogenase (E1 component) Pyruvate + CoA + NAD⁺ → Acetyl-CoA + NADH + CO₂ Impaired entry of pyruvate into the TCA cycle, lactic acid buildup Conversion of α-ketoglutarate to succinyl-CoA α-Ketoglutarate dehydrogenase α-Ketoglutarate + NAD⁺ + CoA →
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1. A scientist is analyzing a pedigree chart to understand the inheritance pattern of a particular disease. Which of the following features in the pedigree chart strongly suggests mitochondrial inheritance? A. Affected males transmit the disease to all their offspring B. The disease appears to skip generations. C. Affected females transmit the disease to all
Genetics- Chromosomal disorders, Mitochondrial inheritance, and Population Genetics Read More »
1. A 7-year-old boy presents with recurrent bacterial and fungal infections. He has a history of abscess formation in multiple organs. His mother is asymptomatic, but her brother had similar infections and died as a child. Genetic analysis reveals a mutation in the gene encoding NADPH oxidase. What is the most likely mode of inheritance?
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Question 1: What is the definition of a single-gene disorder? Answer: Single-gene disorders are genetic conditions caused by mutations in a single gene. They can follow autosomal dominant, autosomal recessive, or X-linked inheritance patterns. Question 2: Name two examples of autosomal dominant single-gene disorders. Answer: Examples include Huntington’s disease and Marfan syndrome. Question 3: What
