Molecules, Genes & Diseases MGD Module PDF

Molecules, Genes & Diseases MGD Module Session 1 Introduction to the Cell and Biological Molecules Lectures 1 Professor Dr.Asaad ,A.B.Alasady 16/2/2023 Recommended Textbooks: Alberts et al. , (2009) Essential Cell Biology 3rd ed Chandar & Viselli (2010) Cell and Molecular Biology. Lippincott’s Ill...

Molecules, Genes & Diseases MGD Module Session 1 Introduction to the Cell and Biological Molecules Lectures 1 Professor Dr.Asaad ,A.B.Alasady 16/2/2023 Recommended Textbooks: Alberts et al. , (2009) Essential Cell Biology 3rd ed Chandar & Viselli (2010) Cell and Molecular Biology. Lippincott’s Illustrated Reviews Read & Donnai ( 2011) New Clinical Genetics 2nd ed Cummings ( 2011) .Human Hereditary 9th ed Learning outcomes At the end of this session you should be able to: 1.List the principal differences between a prokaryotic and an eukaryotic cell. 2.Identify the main organelles in a mammalian cell and list their functions. THE SCIENCE OF CLASSIFICATION Classification Taxonomy - - Grouping objects according to their similar characteristics. The science of classifying living things. Is the more respected classification system. WHY CLASSIFY? ØTo know how many known species there are in the world. ØTo know the characteristics of each species. Useful or harmful ØTo know the relationships between species. 7 6 Kingdom = Largest Group Phylum 5 Class 4 Order 3 Family 2 Genus 1 Species The Kingdoms of organisms Kingdoms * 1-Animalia(animal) 2-Plantae(plant) 3-Fungi(such as mushrooms and yeast) 4-Protista(single-celled organisms with a true nucleus, such as an amoeba ,euglena) 5-Monera[single-celled organisms that lack a true nucleus, such as bacteria, and cyanobacteria (blue-green algae)] Note: During the 1980s,the application of modern molecular techniques has made it clear that there are two very different kinds of bacteria; therefore ,the members were divided into two kingdoms : *Archaebacteria and Eubacteria Kingdom - Animalia Phylum - Chordata (having a spinal cord) Class - Mammalia (have hair, give milk) Order - Primates (walk mostly on 2 legs) Family - Homindae (advanced brain that can think and reason) Genus - Homo Species - sapien Prokaryotic Bacteria Archaea Eukaryotic Unicellular Protists Multi-cellular Fungi Plants Animals These kingdoms include the entire living world it should be obvious that humans are members of the animal kingdom. Free-living cells and the cells of multicellular organisms are subdivided into two major classes: Eukaryotes (true nucleus), and prokaryotes (before nucleus). In Eukaryotes: nucleus separated from the rest of the cell by a membranous envelope. Eu =well or truly Karyon = nucleus Organisms whose cells have a nucleus are called eukaryotic Ex: mammalian cells In Prokaryotes: The nuclear material and rest of the cell are not separated. Lack a nucleus but have nucleoid which has a large DNA molecule. Lack intracellular organelles. Have a cell wall Ex: bacterial cell Cell Components These two groups of cells also differ in many other important respects : Characteristic Prokaryotic cell Cell size 1—10µm Genetic system Organelles Eukaryotic cell * 10 - 100 µm or more *DNA not associated *DNA complexes With protein in with proteins in Chromosomes chromosomes * One linkage group *Two or more (genes along the same Linkage groups Chromosome) *Circular DNA *Linear DNA Molecule is typical molecules. Transient if present Numerous types *Mitochondria, *Lysosome, *Ribosome *Golgi complex etc. Tissue formation Absent Cell division Binary fission budding or other Means, not mitosis Sexual system Present in many groups. various means associated with mitosis. unidirectional transfer Complete nuclear of genes from donor to fusion of equal recipient, if present. gametic genomes associated with meiosis. Motility organelle Simple flagella in bacteria,if present. complex cilia or flagella,if Present. Nutrition Principally absorption, Some photosynthesizer Absorption, ingestion, Photosynthesis. Respiration cytoplasmic membrane mitochondria For aerobic resp. Degradation of Enzymes are secreted extracellular that degrade macrosubstances molecules outside of the Cell. The resulting small molecules are transported into the cell . . macromolecules are brought into the cell by pinocytosis or phagocytes The Cell Cells are the structural and functional units of all living organisms, they are capable of carrying out all the activities necessary for life. Cells are small, membrane enclosed units filled with a concentrated Aqueous Solution of Chemicals and provide with the surprising ability to create copies of themselves by growing and dividing in two. Cell Components 1. Plasma membrane: All living cells are surrounded by a membrane -It is a phospholipid bilayer that responsible for the cell morphology and movement, and transport of ions and small molecules. -It is composed of ;phospholipids, cholesterol ,proteins , and oligosaccharides. **Amphipathic molecule: A molecule that has both a polar (hydrophilic) and non-polar (hydrophobic) end is said to be amphipathic 23 The membrane is selective capable of transporting material in both directions across its 7.5-10nm thickness. (every living cell must have and must maintain an intact plasma membrane if it is to survive). 2. Cytosol : Liquid portion of cytoplasm. (cytoplasm :composed of all materials contained within cytosol). Metabolism of carbohydrates, amino acids and nucleotides, and fatty acid synthesis are carried out in cytoplasm. 3. Organelles: Complex intracellular locations where processes necessary for eukaryotic cellular life occur. Most organelles are membrane enclosed structures, each organelle carries out a specific function. Most cells possess the structures as follow: Endoplasmic reticulum Ribosomes Golgi apparatus Mitochondria Lysosomes Centrioles Vacuoles Peroxisomes Fibrils and microtubules Nucleus, nuclear envelope, chromosomes Nucleolus. Those called living organelles, whereas the non-living organelles or inclusions as follow: Fat, carbohydrates, pigments ,and crystals. Mammalian Cell: Organelles organelles Functions Mammalian Cell: Organelles Functions Nucleus/nucleolus RNA synthesis RNA processing and ribosome assembly( nucleolus) DNA synthesis and repair Ribosome Protein synthesis Endoplasmic reticulum Export of proteins, Membrane synthesis, Lipid and steroid synthesis, Detoxification reactions (Protein synthesis) Golgi complex Export of proteins Mitochondrion ATP synthesis Lysosome Cellular digestion peroxisomes Fatty acids and purine brake down, Detoxification of hydrogen peroxide, and synthesis of cholesterol, bile acids and myelin See tissues of the body module