The course deals with the organization, structure and function of the cell, including biological membranes, cellular organelles and microenvironment. It examines the first step in the flow of genetic information and organization of DNA, and the later steps that end in protein synthesis. Students will study the post-translational modifications, the sorting and targeting of proteins and the mechanisms behind cellular polarity. Emphasis will be given in the structure and role of peroxisomes, lysosomes, endosomes, mitochondria, chloroplasts, cytoskeleton, and of the extracellular matrix. Introduction in the concepts of intra-, extra- and inter-cellular communication, as well as in signal transduction. Alongside, students will learn the research methodology applied in Cell Biology (e.g. Light Microscopy, Transmission Electron Microscopy, Scanning Electron Microscopy, Autoradiography, Cell Fractionation and Electrophoresis), and they will be able to combine and analyze the results obtained by these techniques.

By the end of the lectures and the laboratory exercises, students are expected to be able to: a) describe the organization of a model cellular system, b) identify the composition and function of intra-cellular and extra-cellular structures, c) describe the flow of genetic information from nucleic acids (encoding, storage - packaging and expression of genetic information) to biogenesis of mature, functional proteins (prokaryotic / eukaryotic ribosome and the mechanisms of protein synthesis), d) identify and describe the flow of energy in cells, and the mechanisms of cellular communication, e) select, apply and interpret the results of conventional Cell Biology techniques, such as Electron Microscopy, Protein Electrophoresis and Cellular Fractionation.

At the end of the course students should: Knowledge: a) understand the concepts related to the structure of a model cellular system, such as building blocks, biological membranes, cytoskeleton, cellular organelles and extracellular  matrix, b) identify and explain the organization of the flow of genetic information and cellular organelles, c) describe the mechanisms of protein synthesis and the organelles via which it is performed, d) explain and describe processes of the modification and degradation of bio-molecules in a model cellular system, through mechanisms implicated in the lysosomal - proteasomal degradation, endocytosis/exocytosis and autophagy, e) identify and understand the cell-cycle function, f) explain and understand the processes of signal transduction and intra-/inter-cellular communication of a model animal cell system, g) dissect and describe the mechanisms of production and cellular management of energy and heat, h) identify the post-translational protein modifications, sorting and targeting processes, as well as cellular polarity, i) apply the appropriate research methodology and techniques required to study the structure, organization and operation of a model cellular system – Skills: a) be able to explain the processes of signal transduction and intra-/inter-cellular communication of a model animal cell system, b) manage to handle scientific instruments with ease and reliability, c) have the ability to implement and adapt a research protocol accordingly, d) identify and classify the various cell types, cellular organelles, membranes and extracellular structures, e) develop the ability to examine cellular behavior, with respect to mechanisms governing cellular function and organization – Abilities: a) combine techniques in order to successfully respond to biological questions about the animal cell, b) interpret results, draw conclusions and make new assumptions regarding the structure and operation of an animal system, c) be able to comment on the physiological or pathological organization , flow of information and function of the animal cell, and to review the data, d) develop competence to compare and evaluate data with respect to biogenesis, inter and intra-cellular communication, energy metabolism and cellular response to signal-transduction mechanisms..

INTRODUCTION: STRUCTURAL ELEMENTS - CELLULAR ORGANIZATION (4 Hours): Origin and evolution of organisms. Structural elements - from bio-molecules to cells. Bonds of structural elements and bio-molecules. Cellular organization. Historical overview of Cell Biology. The status of Cell Biology among Biosciences

ORGANIZATION AND FUNCTION OF A MODEL CELLULAR SYSTEM (2 Hours): Dynamics of cellular structure and function. Structure and function of representative cell types. Ultra-structural analysis of cellular organization

RESEARCH METHODOLOGY (4 Hours): Historical flashback of Microscopy. Light Microscopy. Transmission and Scanning Electron Microscopy (TEM and SEM). Immuno-fluorescence. Autoradiography. Cellular fractionation. Electrophoresis. Immuno-blotting. Chromatography. Lectins. Bioinformatics and Cell Biology

BIOLOGICAL MEMBRANES - SEPARATIVE FUNCTIONAL DOUBLE LAYERS (10 Hours): Components of biological membranes. Fluidity and its regulation in organisms. Specialized methodology. Properties of biological membranes. Models describing the structure and function of biological membranes. Specialized membrane systems

FIRST STEP IN THE FLOW OF GENETIC INFORMATION: DNA ORGANIZATION LEVELS (6 Hours): Coding, storage - packaging and decoding of genetic information. Nucleus, nucleolus and chromosomal components. Nuclear envelope, nuclear skeleton and nuclear pores. Human Genome Project (HGP)

SECOND STEP IN THE FLOW OF GENETIC INFORMATION: PROTEIN SYNTHESIS (6 Hours): Protein synthesis. The prokaryotic ribosome. The eukaryotic ribosome. Mechanisms of protein synthesis. Simultaneous translation of an mRNA transcript from multiple ribosomes

POST-TRANSLATIONAL MODIFICATION - PROTEIN SORTING, TARGETING AND CELLULAR POLARITY (5 Hours): Compartmentalization - Fundamental pathways of protein sorting. “Gated” transport of bio-molecules between cytosol and nucleus. Protein transport across membranes. Sorting, transport and protein targeting through vesicle-mediated processes

CELLULAR ORGANELLES THAT PRODUCE AND CONVERT ENERGY: MITOCHONDRIA AND CHLOROPLASTS (5 Hours): Origin, morphology, molecular composition, distribution, biogenesis and function of mitochondria. Structure - Function, relationship. Morphology, composition and function of chloroplasts. Origin and distribution of their molecular components. Structure and function semi-autonomy. Homeostasis of mitochondria population in cells and interactions with other organelles.  Energy conversion mechanism. The electron transport chain.

CELLULAR ORGANELLES THAT  PROCESS AND DEGRADE BIOMOLECULES: PEROXISOMES AND LYSOSOMES (6 Hours): Morphology, molecular composition, distribution, topology, biogenesisand function of peroxisome family members (in animal and plant cells), lysosomes and endosomes. Participation of lysosomes in the processes of endocytosis (pinocytosis and phagocytosis) and autophagy. Contribution of peroxisomes and lysosomes to cellular function, including the release of exosomes.

CELLULAR FIBRILS - CYTOSKELETON (8 Hours): Microfilaments. Actin participation in the cellular mechanisms of movement. Intermediate Filaments (IF). Characteristic types, intracellular organization and distribution of Intermediate Filaments. Microtubules, nucleation mechanisms. Microtubule Organizing Centers (MTOCs). The role of microtubules in mitosis. Cilia and flagella. The Actin-Myosin system. Proteins of thick and thin myofibrils. Interactions of myofibrils with extracellular matrix. Filaments and cellular shape. Microvilli

CELLULAR COMMUNICATION AND CONJUNCTION (3 Hours): Morphological manifestation of communication: Cellular junctions. Communication junctions. Occluding junctions. Anchoring junctions. Cellular adherence. Chemotaxis

EXTRACELLULAR MATRIX (5 Hours): Components, supramolecular organization, architecture, and function of extracellular matrix. Interstitial and pericellular matrix (basal lamina) Collagens and elastins. Glycosaminoglycans (GAGs) and proteoglycans (PGs). Multi-linkers proteins of the extracellular matrix Integrins and cellular receptors of extracellular matrix. Plant cell wall.

CELL CYCLE - REPRODUCTION (4 Hours): Cell growth and division. Inter-phase. Cell-cycle regulation during inter-phase. Cell-cycle progression and the distinct restriction - check points. Regulation of cell-cycle check points. Mitosis and cytokinesis. Mechanisms controlling mitosis. Meiosis. Stages of the meiotic divisions I and II

PRINCIPLES OF SIGNAL TRANSDUCTION (4 Hours): Role of protein phosphorylation in signal transduction. Classification of biological signals. Growth Factors (GFs). Epidermal Growth Factor Receptor (EGFR). Role of signal transduction in cellular differentiation and development

The average grade of Laboratory Exercises contributes 30% to the final, total, course grade. Each exercise grade results from the examination performed during the exercise-laboratory hours and written quiz (exercises 7 and 8)