Comprehensive Biology Syllabus and Study Guide (Filter Semester)
Prerequisites and Integral Objectives of the Biology Course
The Teaching of Biology in the Filter Semester is conducted in Italian and requires a foundational knowledge base in mathematics, physics, chemistry, and biology. This preparation should align with the educational standards established by national guidelines for Italian high schools (licei), technical institutes, and professional institutes. The primary general objective of the course is to provide students with a robust and integrated understanding of biological foundations. This knowledge serves as an indispensable prerequisite for understanding physiological and pathological processes, which are addressed in subsequent biomedical coursework.
Specific learning objectives are categorized into several domains. Regarding knowledge and understanding, students must be able to describe the structure and function of major biological macromolecules and understand the molecular bases of living matter. They are expected to comprehend cellular organization, compartmentalization, intracellular trafficking, and the interactions between cells and their external environment. Furthermore, the course aims to illustrate molecular and cellular mechanisms regulating genetic and epigenetic expression and transmission, including their implications in hereditary pathologies. Students will also explore the foundations of cellular communication, signal transduction, the control of proliferation and cell death, and the processes of mitosis and meiosis in germ cells.
In terms of applying knowledge, students should be capable of using biological tenets to interpret normal and pathological cellular processes relevant to the medical field. This includes interpreting experimental data related to cell structure, gene regulation, and signaling mechanisms. Additionally, students are expected to develop autonomy of judgment, allowing them to critically evaluate information, form informed opinions, and make independent decisions. Communication skills are also prioritized, requiring students to express knowledge clearly and effectively. Finally, the capacity for learning focuses on enabling autonomous and continuous professional updating.
Unit 1: Foundations of Biological and Molecular Organization
This unit, valued at CFU, covers the foundational properties of life and the diversity of organisms. It begins with the tree of life, cellular theory, and the fundamental properties of living matter. A significant portion is dedicated to viruses, covering their general characteristics, including nucleic acids, the capsid, and the membranous envelope. The course examines various classes of animal viruses, the lytic and lysogenic cycles of bacterial viruses (bacteriophages), the specific cycles of animal viruses and retroviruses, and the mechanisms by which viruses enter and exit animal cells.
Prokaryotic cells are analyzed in detail, focusing on structures such as the plasma membrane, cell wall, external membrane, capsule, fimbriae, pili, and flagella. This includes the distinction between Gram-positive and Gram-negative bacteria via the Gram staining method, as well as the differentiation between eubacteria and archaebacteria. The unit also addresses horizontal gene transfer in bacteria through transformation, conjugation, and transduction, highlighting their biological importance. Eukaryotic studies focus on the endomembrane system, the generation of the nucleus, and the endosymbiotic theory for mitochondrial generation, tracing the transition from unicellular to complex multicellular organisms.
The molecular foundation involves the structure and function of biological macromolecules: sugars, carbohydrates, lipids, and amino acids. Protein study includes the peptide bond, protein structure, domains, and active sites. Enzymes are used as primary examples, specifically focusing on classes like kinase-phosphatase, ubiquitinase-deubiquitinase, and acetylase-deacetylase. Major post-translational modifications such as phosphorylation, acetylation, glycosylation, and the addition of lipids are covered. The unit concludes with nucleotides and nucleic acids, focusing on the Watson and Crick model of the DNA double helix, the structure and function of various coding and non-coding RNAs, and basic metabolism, including anabolism, catabolism, condensation reactions, and hydrolysis.
Unit 2: Cellular Mechanisms of Genetic and Epigenetic Transmission
Weighted at CFU, this unit explores the eukaryotic genome and chromatin organization. Eukaryotic genomes consist of linear chromosomes with specific minimal organizational requirements, including centromeric and telomeric DNA. Chromatin structure is explored through the study of nucleosomes, DNA packing with histone proteins, the role of histone H1, and the formation of the fiber. The distinction between euchromatin and heterochromatin is established alongside the role of DNA methylation.
Epigenetics is central to this unit, highlighting the remodeling of chromatin and the post-translational modifications of histones, specifically acetylation. The role of condensins in chromatin folding is also discussed. The human genome is detailed by its sequence characteristics: single sequences, gene families (such as globins and ribosomal RNA), and various repeated sequences. These include tandem repeats like minisatellites and microsatellites, as well as interspersed repeated sequences such as LINEs, SINEs, and endogenous retroviruses. DNA mobile elements are also covered as part of the genomic landscape.
Unit 3: The Flow of Genetic Information
This unit carries a weight of CFU and provides an exhaustive look at DNA replication, transcription, and translation. DNA replication in both prokaryotes and eukaryotes is described as a semiconservative mechanism. Key concepts include origins of replication, the initiation complex, and the replication fork. Molecular actors such as DNA helicase, topoisomerase, primase (and RNA primers), DNA polymerases (including proofreading activity), continuous and discontinuous strands, Okazaki fragments, and DNA ligase are all detailed. The role of telomeres and telomerase is discussed in the context of replicative senescence.
The anatomy of the gene is contrasted between prokaryotes and eukaryotes, covering monocistronic and polycistronic genes, promoters, and cis-regulatory elements. Transcriptional regulation is introduced via the Lac operon model in prokaryotes. In eukaryotes, the control of gene expression spans transcriptional, post-transcriptional, translational, and post-translational levels. Eukaryotic transcription involves three RNA polymerases (I, II, and III), general transcription factors, the TATA box, and proximal/distal promoters (enhancers and silencers). Specific factors like steroid hormone receptors are used to illustrate regulation.
RNA maturation processes include capping, polyadenylation, splicing, and alternative splicing mediated by the spliceosome and snRNAs. Ribozymes and RNA editing are introduced, along with the regulation of messenger RNA stability through deadenylation, decapping, miRNA, and RNA interference (RNAi). The unit details the maturation of rRNA and tRNA. Protein synthesis (translation) is broken down by its actors (rRNA, tRNA, mRNA) and stages: aminoacyl-tRNA formation, ribosome function, and the properties of the genetic code (redundancy, degeneracy, non-ambiguity, and universality). The role of UTRs (untranslated regions) and factors for initiation, elongation, and termination are covered. Finally, protein maturation (folding) by chaperones, misfolding errors, and degradation through the ubiquitin-dependent proteasomal system are explained.
Unit 4: Transmission of Wild-Type and Mutated Characters
At CFU, this unit focuses on genome variations and inheritance patterns. It covers nucleotide substitutions, insertions, and deletions, as well as genic and chromosomal mutations like the expansion of repeated sequences. DNA repair mechanisms for single and double-strand damage are detailed. Mendelian genetics is explored through alleles (homozygosity, heterozygosity, compound heterozygosity), dominance, recessivity, genotype, phenotype, segregation, and independent assortment. Complex inheritance patterns include incomplete dominance, codominance, multiple alleles (AB0 blood group system), pleiotropy, epistasis, and genetic mapping.
Gene expression modulation by the environment is discussed via penetrance, expressivity, polygenic traits, quantitative inheritance, and genomic imprinting. Human cytogenetics is covered through the study of chromosomes and the karyotype, focusing on diploidy, homologous chromosomes, and banding techniques. Chromosomal alterations include variations in number (aneuploidy, polyploidy) and structure (translocations, inversions, deletions, and insertions), with Trisomy 21 provided as a primary example. Pedigree analysis includes autosomal (dominant and recessive), X-linked, Y-linked, and mitochondrial inheritance patterns.
Unit 5: Cellular Structures: Biogenesis, Morphology, and Functions
This unit is the most extensive at CFU. It begins with membrane structure, the fluid mosaic model, the glycocalyx, and membrane asymmetry. Transport mechanisms include osmosis, diffusion, passive transport, channel proteins, and transporters. Active transport is exemplified by ATPase pumps and ABC transporters, linking these to membrane and action potentials. Protein sorting is handled by discussing cellular compartments, topological relationships, and addressing signal sequences.
The nucleus is studied through the nuclear envelope, nucleolus, nuclear condensates, and nuclear pores (nucleoporins). Nuclear transport relies on importins, exportins, Ran protein, RanGEF, and RanGAP, with regulation exemplified by NFkB and SREBP1. Mitochondria are analyzed for their structure, genome, bioenergetics (glycolysis, TCA cycle, electron transport chain, ATP synthesis), and dynamics (fusion and fission). Mitochondrial protein import involves the TOM, TIM, SAM, and OXA translocators. Peroxisomes are covered regarding biosynthetic and catabolic functions, signal-mediated transport (peroxins), and associated pathologies like Zellweger syndrome.
The secretory pathway involves the endoplasmic reticulum (smooth and rough), the Golgi apparatus (cis and trans networks), and vesicular trafficking. Key concepts include SRP, the translocon, signal peptidase, glycosylation, and quality control (calnexin/calreticulin). The UPR response, ERAD system, and Cystic Fibrosis are used as clinical context. Vesicle formation and docking involve coating proteins, NSF, SNAPs, SNAREs, Rab proteins, and phosphoinositides. Endocytosis types (fluid-phase, receptor-mediated) are contrasted through transferrin, LDL, and EGF pathways. Further topics include lysosomes (mannose-6-phosphate), autophagy (macro/micro/chaperone-mediated), and the cytoskeleton (microtubules, GTP, dyeins, kinesins, microfilaments, actin, Arp2/3, Rho family, intermediate filaments, and keratins).
Unit 6: Cell and Environment, Signaling, and Transduction
Valued at CFU, this unit covers the extracellular matrix (ECM) structure, function, and degradation. Anchoring to the matrix occurs via integrins, and the unit explores mechanotransduction and fibronectin. Communication between cells involves recognition via cadherins and CAMs, leading to specialized junctions: occluding (tight) junctions, adherent junctions, desmosomes, hemidesmosomes, and gap (communicating) junctions.
Cell signaling is classified by distance: contact-dependent, autocrine, paracrine, endocrine, and synaptic. Transduction cascades involve membrane and intracellular receptors, with examples like nitric oxide and lipid hormones. Specific receptor classes include ion-channel-coupled receptors, G-protein-coupled receptors (GPCRs) with monomeric and trimeric G proteins, and regulatory GEF/GAP proteins. Signaling amplification through second messengers and receptor desensitization (example of vision) is covered. Enzyme-linked receptors, particularly receptor tyrosine kinases (RTKs) and the Ras-MAP kinase pathway, are linked to oncogenes and insulin/EGF signaling.
Unit 7: Control of Proliferation and Cell Survival
This final unit ( CFU) focuses on the cell cycle, mitosis, meiosis, and death. The cell cycle is regulated by cyclins and cyclin-dependent kinases (CDKs) at specific checkpoints. The restriction point and entry into S-phase are modulated by growth factors, cyclin D-Cdk4/6, Rb phosphorylation, and E2F activation. Inhibitors of these complexes and the role of p53 in DNA damage (repair vs. apoptosis) are detailed. This section also defines proto-oncogenes, oncogenes, and tumor suppressor genes.
Mitosis is described phase-by-phase, covering entry, chromosome condensation, and the mitotic spindle (astral, kinetochore, and interpolar microtubules). Molecular mechanisms include the NDC80 complex, the APC/C (cyclosome) for cyclin/securin degradation, and chromatid separation. Meiosis is explored through its genetic consequences, crossing over, and differences from mitosis. The unit addresses the causes of aneuploidy and the specifics of meiosis in male and female human gametogenesis, alongside the concept of stem cells. Finally, cell death is contrasted between necrosis and apoptosis. Apoptosis is detailed via intrinsic and extrinsic pathways, involving initiator and executioner caspases, MOMP, cytochrome C, the apoptosome, the BCL2 family (pro- and anti-apoptotic proteins), and death receptors.