Biochemistry of Metabolism
ΒΒ0403 | ECTS: 6
Theory: 4 hours/week | Practicals: 3 hours/week
Learning Outcomes
The primary aim of the course is to provide students with a comprehensive understanding of the fundamental principles and regulatory mechanisms governing the biochemical processes related to energy metabolism, the integration and control of metabolism at the cellular, organ-system, and whole-organism levels. These topics are examined under various physiological and pathological conditions, including rest, food intake, changes in energy demand, exercise, starvation, and metabolic disorders.
Upon successful completion of the course, students are expected to:
- Demonstrate knowledge of, and the ability to describe, the basic concepts and principles of metabolism.
- Attain an in-depth understanding of the mechanisms of energy generation, transformation, and storage, with particular emphasis on carbohydrate and fatty acid metabolism, the Krebs cycle, the respiratory chain–oxidative phosphorylation system, and the pentose phosphate pathway.
- Understand the biochemical mechanisms underlying the control and integration of metabolism at the cellular, organ-system, and whole-organism levels.
- Synthesize knowledge and apply critical thinking skills to identify metabolic alterations occurring under varying conditions of nutrient availability and energy requirements.
- Integrate theoretical knowledge with experimental experience to compare and distinguish the differential activation of carbohydrate and fatty acid metabolism, the Krebs cycle, the respiratory chain–oxidative phosphorylation system, and glycogen metabolism across different cell types.
- Develop practical laboratory skills and the ability to collaborate effectively with peers in conducting laboratory exercises, as well as in analyzing and evaluating experimental results.
Analytical Description of the Course
- Fundamental concepts of signal transduction and intercellular communication. Mechanisms of glucagon, insulin, and steroid hormone signaling. Calcium ions as second messengers.
- Fundamental principles of metabolism. General framework of metabolic regulation. Roles of coupled reactions and ATP production.
- Oxidation of organic molecules as a source of cellular energy.
- Sources of glucose. Glycolysis as an energy-conversion pathway.
- Entry of carbohydrates into the glycolytic pathway.
- Biochemical pathways of NAD⁺ regeneration.
- Pathological conditions associated with dysregulation of fructose and galactose metabolism.
- Aerobic glycolysis in rapidly proliferating cells.
- Gluconeogenesis: synthesis of glucose from non-carbohydrate precursors.
- Regulation of glycolysis and gluconeogenesis.
- The Cori cycle.
- Pyruvate dehydrogenase: the link between glycolysis and the citric acid cycle. Mechanisms and regulation of enzyme activity.
- The citric acid (Krebs) cycle: reactions and regulatory control mechanisms.
- The citric acid cycle as a source of biosynthetic precursors.
- Dysregulation of pyruvate metabolism. A cause of beriberi, and its role in mercury and arsenic poisoning.
- The glyoxylate cycle.
- Respiratory chain complexes.
- ATP synthase: ATP synthesis driven by the proton gradient; coupling of the respiratory chain and oxidative phosphorylation.
- Regulation of oxidative phosphorylation by cellular ATP demand. Regulation of ATP synthase activity. Cellular respiration.
- Selective transport across mitochondrial membranes. Electron transfer from cytoplasmic NADH to mitochondria.
- ATP–ADP translocation.
- Heat generation through uncoupling of the respiratory chain and oxidative phosphorylation.
- Inhibitors of the respiratory chain and uncouplers of oxidative phosphorylation (OXPHOS).
- OXPHOS dysfunction and mitochondrial-associated diseases.
- The Calvin cycle and its regulation.
- The pentose phosphate pathway. The role of NADPH in anabolic pathways. Role of glucose-6-phosphate dehydrogenase in protection against reactive oxygen species.
- Glycogen metabolism: glycogen structure, glycogen granules, glycogen degradation and synthesis, signaling and hormonal regulation of glycogen metabolism, enzyme regulation, and glycogen-related diseases.
- Fatty acid metabolism: mobilization of triacylglycerols, β-oxidation of fatty acids, and de novo fatty acid synthesis. Regulation of fatty acid metabolism.
- Caloric homeostasis as a regulator of body mass.
- The role of the brain in regulating caloric homeostasis.
- Leptin and insulin as regulators of the long-term control of caloric homeostasis. The role of leptin resistance in obesity.
- Metabolic alterations caused by excess fatty acids in muscle.
- Insulin signal transduction in muscle. Muscle insulin resistance and its contribution to pancreatic insufficiency.
- Metabolic disturbances in type I and type II diabetes. The role of obesity in the development of diabetes.
- Effects of physical exercise on cellular metabolism.
- Metabolic changes during feeding and starvation.
- Effect of ethanol on liver metabolism
Laboratory Exercises
- Design of biochemical experiments and data analysis
- Reference curve
- Determination of kinetic parameters of alkaline phosphatase
- Mitochondrial Redox systems: A) Distribution of respiratory enzymes in cells; B) Subcellular localization of succinate dehydrogenase; C) Effect of malonic acid on succinate dehydrogenase activity; D) Effect of exogenous NAD on glutamate dehydrogenase activity.
- Glycogen metabolism in liver: Determination of A) free phosphate and B) lactic acid in liver
- Glycogen metabolism in muscle: Determination of A) free phosphate and B) lactic acid in muscle.
Student Performance Evaluation
Students’ performance is evaluated through written examinations at the end of the semester (80%), short written assessments on laboratory exercises (10%), and short laboratory exams (10%), with the latter consisting of multiple-choice questions related to each laboratory exercise. Additionally, an optional assignment is provided at the beginning of the semester, based on a scientific publication relevant to the course content. Students are expected to critically analyze the publication and present their findings in a 10-minute presentation, followed by a 5-minute question-and-answer session, at the end of the semester, prior to the written examinations. Successful completion of this assignment contribute up to an additional 10% to the final grade.
Suggested Bibliography
- BIOCHEMISTRY, BERG J.M., TYMOCZKO J.L., STRYER LUBERT
- METABOLIC REGULATION AT THE MOLECULAR LEVEL, GEORGATSOS I, GIANNAKOUROS TH.
- BIOCHEMISTRY, KARLSON PETER
- LEHNINGER PRINCIPLES OF BIOCHEMISTRY, Nelson D., Cox M.
- BIOCHEMISTRY, Raymond S. Ochs
Teaching Material / E-class
Lecturers
Anna-Maria Psarra (Course Coordinator)
Vasiliki Skamnaki
