BCM 261: Lipid and Nitrogen Metabolism

Introduction

This module provides an in-depth exploration of the biochemistry of lipids and nitrogen-containing macromolecules, focusing on their metabolism, regulation, and associated diseases. The course is structured to build upon foundational knowledge from previous biochemistry modules, emphasizing both theoretical understanding and practical application.

Module Structure and Main Themes

Theme 1: Biosynthesis of Amino Acids and Nucleic Acids

• Nitrogen Cycle: Overview of key processes, including biological and abiotic nitrogen fixation, and regulatory mechanisms of enzymes involved in nitrogen metabolism.

• Assimilation of Ammonia: Transamination reactions, roles of glutamate and glutamine, and the enzymes and cofactors involved.

• Amino Acid Biosynthesis: Essential vs. non-essential amino acids, precursor molecules, biosynthetic pathways, and enzyme mechanisms.

• Biosynthesis of Purines and Pyrimidines: Structural and functional differences among nucleobases, nucleotides, and nucleosides; de novo and salvage pathways.

Theme 2: Nitrogen Excretion and Derivatives of Amino Acids and Nucleic Acids

• Amino Acid Catabolism: Classification of ketogenic and glucogenic amino acids, catabolic pathways, and entry points into the citric acid cycle.

• Nitrogen Excretion: Differences among ammoniotelic, ureotelic, and uricotelic animals; purine and pyrimidine catabolism; urea cycle and its regulation.

• Applications and Diseases: Synthesis of key molecules (e.g., neurotransmitters, pigments), inborn errors of metabolism, and the role of vitamins in biosynthesis and degradation.

Theme 3: Digestion, Mobilization, and Transport of Lipids

• Lipid Storage and Fuel: Efficiency of fats as fuel, sources of fatty acids, and mechanisms of absorption and transport.

• Fatty Acid Oxidation: Stages of β-oxidation, activation and transport of fatty acids, and energy yield calculations.

• Oxidative Phosphorylation: Chemiosmotic theory, electron transport chain components, ATP synthase, and coupling of electron transport to phosphorylation.

• Additional Pathways: Oxidation of odd-numbered and unsaturated fatty acids, ketone body formation, and metabolic water production.

Theme 4: Fatty Acid Synthesis and Lipid Biosynthesis

• Fatty Acid Synthesis: Regulation, activation of acetyl-CoA, role of CO2, fatty acid synthase complex, and differences between prokaryotes and eukaryotes.

• Elongation and Desaturation: Subcellular locations, essential fatty acids, and ω-3/ω-6 pathways.

• Triacylglycerol and Membrane Lipid Synthesis: Biosynthesis pathways, regulation by insulin, and synthesis of glycerophospholipids and sphingolipids.

• Cholesterol and Isoprenoid Metabolism: Cholesterol biosynthesis, regulation, transport, lipoprotein function, and implications for heart disease.

Assessment Overview

• Semester Tests: Two tests, each contributing 28% to the semester mark.

• Theme Assignments: Four graded assignments via Achieve, contributing 14% to the semester mark.

• Practicals: Compulsory online practical assessments, contributing 30% to the semester mark.

• Examination: Final exam and supplementary exam opportunities, with specific admission requirements.

Key Learning Outcomes

• Understand and describe the biochemical pathways of lipid and nitrogen metabolism.

• Identify and explain the regulation of metabolic enzymes and pathways.

• Apply knowledge to calculate bioenergetics and analyze metabolic diseases.

• Demonstrate practical skills in scientific reading, writing, and experimental techniques.

Recommended Study Practices

• Attend all lectures and practical sessions for comprehensive understanding.

• Use the prescribed textbook (Lehninger Principles of Biochemistry, 8th edition) and Achieve platform for self-study and assignments.

• Supplement lecture notes with textbook readings and personal notes.

• Engage actively with online quizzes and assignments to reinforce learning.

Administrative and Contact Information

• All module-related queries should be posted on the ClickUP Discussion Board.

• Private matters (e.g., health, religious reasons) should be communicated via email, following the specified format.

• Consultation hours and contact details for lecturers, practical coordinators, and administrators are provided in the module guide.