MOLECULAR BIOENERGETICS

To provide an integrated view of mitochondrial bioenergetics with emphasis on the molecular aspects of it. Three-dimensional structures and nucleotide and amino acid sequences will be considered in a general framework. The cellular and metabolic role of the mitochondrion will be described with reference to the structural detail of the molecules involved. The biomolecular importance of the organelle will be addressed in the round, from the energetic to the biochemical, nutritional, genetic, evolutionary and disease-related aspects.

The course will be delivered through lectures and seminar sessions. The use of telematic and computer tools will add depth to the course. Students will be actively involved.

If the course is taught in a blended mode or at a distance, the necessary variations may be introduced in order to comply with the syllabus.

The Bachelor's degree provides sufficient preparation for successful completion of the course.

Class attendance is necessary for a better understanding of the contents. In fact, an important part of the CFUs will be used for in-depth study of literature for which the lessons are critical and indispensable moments of coordination.
In any case, the minimum attendance will follow the guidelines of the Degree Course.
In addition, practical exercises will be organised on respirometric methods for studying mitochondrial activity and the reconstitution of porins in planar lipid membranes.

The roles of the mitochondrion in the cell and the organism.
Structural organisation of the mitochondrion, topology from EM to TAC-EM. Phospholipid composition of mitochondrial membranes. Contact sites between mitochondrion and other cytoplasmic organelles.
Elements of General Bioenergetics. Free energy. Phosphorylated compounds and their importance.
Mitochondrial metabolisms: catabolic pathways and production of energy molecules; biosynthesis of structural and functional intermediates; control of cellular redox balance; management of waste products.
Relationship between biological energy and nutrition. The energy balance of living organisms. The final fate of nutrients is in the mitochondrion. The management of food-derived energy takes place in the mitochondrion. Energy metabolism. Energy demand and optimal energy expenditure. The mitochondrion as a regulatory centre for energy homeostasis.
Central role of the membranes. Energised state of membranes. Chemiosmotic hypothesis and its demonstration. Oxidative phosphorylation: the machinery involved. Structural biology of the bioenergetic machinery.
Organisation of the respiratory chain. Techniques used to study mitochondrial function: Clark's electrode, high-resolution respirometry; use of fluorescent markers to determine membrane potential. 3D structure of respiratory chain complexes. Complexes I-IV. Co-Q and cytochrome c. Mitochondrial super-complexes.
Oxidative phosphorylation, deciphering the mechanism of ATP synthesis. 3D structure of ATPsynthase.
Carriers and transporters in the mitochondrion. Structure. Transport mechanisms, study methods, reconstitution in artificial membranes. The pores of the outer membrane: 3D structure, biophysical study methods.
Mitochondrial biogenesis. The coordinated contribution of nuclear and mitochondrial DNA to the constitution of the organelle. Protein import routes. Coordination of the transcription of the two genomes. Study methods. Adaptation to environmental conditions.
The genetic system of the mitochondrion. Endosymbiont theory of mitochondrial origin. The mitochondrial genome in different species is variable. human mtDNA: organisation of genes. Genetic metabolism machinery. Protein synthesis and use of the non-universal genetic code. The particular heredity of the organelle. Mitochondrial mutations. Heteroplasmia and homoplasmia. Mitochondrial pathologies due to mtDNA mutation. Mitochondrial evolution. Use of mtDNA in population genetics and species recognition (DNA barcoding).
Proteomics of the mitochondrion. Methods and results of a large-scale study.

This is an inter- and meta-disciplinary course, for which there are no canonical textbooks. The study material will be provided by the lecturer and will consist of articles from the literature and material projected in class. Both will be uploaded to Studium.
As a general reference you may find helpful: Nichols DG, Ferguson S - Bioenergetics 4th ed 2014 Academic Press editor and later editions. Also the classical textbook by A.L. Lehninger provides a well written chapter about the basics of Bioenergetics and general biochemical insights.

Projected presentations and discussed articles will be uploaded to Studium immediately after the lecture.

The examination method is an oral interview. During this interview, the candidate may present an in-depth study of a topic agreed with the teacher.
The learning assessment may also be carried out electronically, should the conditions require it.

What is the organization of the electronic transport chain?