Introduction To Medical Biology And Genetics PDF

Introduction to Medical Biology and Genetics Dr. Hilal Eren Gözel Department of Medical Biology & Genetics, Faculty of Medicine I. Okan University Contact Info [email protected] 1st Floor, Room #129 COURSE SCHEDULE FOR 101 Intro. to Medical Biology and Genetics Dr. Hilal EREN GÖZEL Cellular Str...

Introduction to Medical Biology and Genetics Dr. Hilal Eren Gözel Department of Medical Biology & Genetics, Faculty of Medicine I. Okan University Contact Info [email protected] 1st Floor, Room #129 COURSE SCHEDULE FOR 101 Intro. to Medical Biology and Genetics Dr. Hilal EREN GÖZEL Cellular Structures and Organelles Dr. Hilal EREN GÖZEL Cytoskeleton Dr. Hilal EREN GÖZEL Cell Membrane & Membrane transport Dr. Hilal EREN GÖZEL DNA structure & function, replication Dr. Müge ATIŞ CEYLAN RNA structure & function, Transcription Dr. Müge ATIŞ CEYLAN Transcriptional regulation Dr. Müge ATIŞ CEYLAN Posttranscriptional regulation Dr. Müge ATIŞ CEYLAN Review / Problem Solving Dr. Hilal EREN GÖZEL Dr. Müge ATIŞ CEYLAN Objectives of 101 Students should know about cellular structures, cytoskeleton, cell membrane and organelles, They should be able to explain diseases related to cellular structures Students should know the structure and function of nucleic acids, explain the events (replication, transcription and their regulation) related to them. What does it mean to be living? 2 Universal features of cells Chapter 1: Cells and Genomes (A) (B) (C) 100 µm (E) 50 µm (D) Sea Urchin FEATURES OF CELLS Mouse THE UNIVERSAL ON EARTH It is estimated that there are more than 10 million—perhaps 100 million—living species on Earth today. Each species is different, and each reproduces itself faithfully, yielding progeny that belong to the same species: the parent organism hands 50 µm (F) Fucus sp - Seaweed Figure 1–1 The hereditary information in the fertilized egg cell determines the nature of the whole multicellular organism. Although their starting cells look superficially similar, as indicated: a sea urchin egg gives rise to a sea urchin Universal features of cells There are more than 10 million species on Earth. Although each species is different, they all reproduce yielding a progeny that represent the copies of themselves (Heredity). This hereditary information drives a complex system of chemical processes that are crucial for the cell organization and its survival. Universal features of cells Although, the organisms can be unicellular or multicellular(like us), the whole organism has been generated by cell divisions from a single cell. The single cell, therefore, is the vehicle for all of the hereditary information that defines each species. Universal features of cells All cells store their hereditary information in the same chemical code system: DNA (or RNA for viruses) DNA or RNA codes (A, C, G, T or U) and their structures are universal in all organisms. The mechanisms that take part in reading the hereditary information (Protein synthesis) or replication of it, occur very similarly in different species. Universal features of cells All cells use proteins as catalysts (to increase rate of chemical reactions). All cells use ATP as their free energy source. All cells are enclosed in a plasma membrane across which nutrients and waste materials must pass. All cells have ribosomes. Similar And Different! Diversity of cells Differences of Cells: Size Shape Chemical requirements 1 mm Similar And Different! The scientific study of how living things are classified is called taxonomy. Similar And Different! The binomial nomenclature system combines two names into one to give all species unique scientific names. Divisions of life Cells are the basic structural and functional units of every organism. They have two distinct types: Prokaryotic and Eukaryotic. Prokaryotic cells: Bacteria and Archaea Eukaryotik cells: Protists, fungi, animals, and plants Prion, Viroid and Virus!!! Divisions of life Prokaryotic cells Eukaryotic cells No nuclear membrane (Nucleoid) True nucleus, consisting of nuclear membrane No Membrane-enclosed organelles Lysosomes, Golgi complex, endoplasmic reticulum, mitochondria & chloroplasts Cell Wall: Usually present; chemically complex (typical bacterial cell wall includes peptidoglycan) Cell Wall: When present, chemically simple Plasma membrane: No carbohydrates and generally lacks sterols Plasma membrane: Sterols and carbohydrates that serve as receptors present Cytoplasm: Simpler cytoskeleton Cytoplasm: Cytoskeleton; cytoplasmic streaming Ribosomes smaller in size (70S) Larger size (80S) Single circular DNA, lacks histones Linear DNA with histones Cell division: Binary Division Cell division: Mitosis Sexual reproduction: No meiosis; transfer of DNA fragments only (conjugation) Meiosis Divisions of life present in mal cells, cluster of within an he plasma membrane (ribosome-studded) and smooth regions Rough ER Smooth ER Nucleolus: nonmembranous structure involved in production NUCLEUS of ribosomes; a nucleus has Nuclear envelope one or more nucleoli NUCLEUS Chromatin: material consisting of DNA and proteins; visible in a dividing cell as individual condensed chromosomes me: region the cell’s bules are ontains a centrioles Nucleolus Chromatin Plasma membrane: membrane enclosing the cell N: shape; movement; e made of es: Golgi apparatus ANIMATION Rough endoplasmic reticulum www.mast BioFlix® 3-D Animal Cell Smooth endoplasmic reticulum Ribosomes (small b Central vacuole: promin in older plant cells; func breakdown of waste pr macromolecules; enlarg major mechanism of pla Microfilament Intermediate filaments aments Microtubules aments Ribosomes (small brown dots): complexes that make proteins; free in cytosol or bound to rough ER or nuclear Mitochondrion envelope tubules Peroxisome li: at l’s ea ganelle ecialized ions; Plasma membrane Cell wall: outer layer that maintains Golgi apparatus: organelle active cell’s shape and protects cell from in synthesis, modification, sorting, mechanical damage; made of cellulose, and secretion of cell products other polysaccharides, and protein Wall of adjacent cell Mitochondrion: organelle where Lysosome: digestive organelle where In animal cells but not plant cells: Lysosomes Chloroplast: photosynthe organelle; converts energ sunlight to chemical ener stored in sugar molecules Plasmodesmata: cytoplasmic channels through cell walls that connect the cytoplasms of adjacent cells In plant cell Chloroplast Central vacu Cell wall Plasmodesm Differences Between Plant and Animal Cells Differences Between Plant and Animal Cells Divisions of life Prion (Proteinaceous infectious particle): Prions are not considered living organisms because they are misfolded protein molecules which may propagate by transmitting a misfolded protein state. If a prion enters a healthy organism, it induces existing, properly folded proteins to convert into the misfolded prion form. In this way, the prion acts as a template to guide the misfolding of more proteins into prion form. Divisions of life PRION Divisions of life Bovine spongiform encephalopathy (BSE): It is commonly known as mad cow disease, is a neurodegenerative disease of cattle. Symptoms include abnormal behavior, trouble walking, and weight loss. Time from onset of symptoms to death is generally weeks to months. Divisions of life Creutzfeldt–Jakob disease (CJD): It is a form of brain damage that leads to a rapid decrease of movement and mental function. Divisions of life - Virus Virus: A virus is a small infectious agent that replicates only inside the living cells of other organisms. They reproduce by creating multiple copies of themselves through self-assembly by using host’s metabolism. This infectious particle consisting of nucleic acid enclosed in a protein coat(capsid) and, for some viruses, surrounded by a membranous envelope. Divisions of life – Virus No organelles, only some genes. Their genomes may consist of double-stranded DNA, singlestranded DNA, double-stranded RNA, or single-stranded RNA, depending on the type of virus. Divisions of life RNA Capsomere Virus: DNA Membranous envelope RNA Capsid Head Capsomere of capsid DNA Tail sheath Tail fiber Glycoprotein 18 × 250 nm Glycoproteins 70–90 nm (diameter) 20 nm (a) Tobacco mosaic virus has a helical capsid with the overall shape of a rigid rod. 50 nm (b) Adenoviruses have an icosahedral capsid with a glycoprotein spike at each vertex. 80–200 nm (diameter) 50 nm (c) Influenza viruses have an outer envelope studded with glycoprotein spikes. The genome consists of eight different RNA molecules, each wrapped in a helical capsid. 80 × 225 nm 50 nm (d) Bacteriophage T4, like other “T-even” phages, has a complex capsid consisting of an icosahedral head and a tail apparatus. Science! The word science is derived from a Latin verb meaning “to know.” Science! Science is an approach to understanding the natural world. It developed out of our curiosity about ourselves, other lifeforms, our planet, and the universe. At the heart of science is inquiry, a search for information and explanation, often focusing on specific questions. Hypothesis Scientists attempt to understand how natural phenomena work using a process of inquiry that includes making observations, forming logical hypotheses, and testing them. The process is necessarily repetitive: In testing a hypothesis, more observations may force formation of a new hypothesis or revision of the original one, and further testing. Flashlight doesn’t work. The Scientific Method Why doesn’t the flashlight work? The Scientific Method Theories in Science A scientific theory is an explanation of an aspect of the natural world that can be repeatedly tested and verified in accordance with the scientific method, using accepted protocols of observation, measurement, and evaluation of results. A theory is general enough to spin off many new, specific hypotheses that can be tested. Cell sizes 1 meter = 1000 millimeters = 1.000.000 micrometers = 1.000.000.000 nanometers https://courses.candelalearning.com/biology11xmaster/chapter/comparing-prokaryotic-and-eukaryotic-cells/ Cell sizes http://learn.genetics.utah.edu/content/cells/scale/ Scan me! Levels of Organization Cell Cells are the smallest units that still retain the characteristics of life, including complex organization, metabolic activity and reproductive behavior. 1665, Robert Hooke observed tiny, empty compartments of a thinly sliced piece of cork under microscope. He gave them the Latin name «cellulae» (small rooms) Cell theory «Schleiden» 1838 - Plant tissues are made of cells. «Schwann» 1839 - Animal tissues are made of cells. All living organisms are composed of one or more cells. The cell is the basic living unit of organization for all organisms. All cells arise from preexisting cells. References