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First Week Gihan E-H Gawish, MSc, PhD Ass. Professor Molecular Genetics and Clinical Biochemistry Molecular Genetics and Clinical BiochemistryKSU
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What is the molecular biology science? And Why it is important to study?!
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Molecular biology; the study of gene structure and functions at the molecular level to understand the molecular basis of hereditary, genetic variation and the expression patterns of genes Molecular Biology
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DNA the molecule of life
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The totality of genetic information and is encoded in the DNA (or, for some viruses, RNA) The Genome
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The genetic material of all cellular organisms and most viruses, the gigantic molecule which is used to encode genetic information for all life on Earth.
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The Chromosome http://www.johnkyrk.com/ch romosomestructure.html The storage place for all genetic information, the number of chromosomes varies from one species to another.
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In normal human cell DNA contained in the nucleus, arranged in 23 pairs of chromosomes. 22 pairs of chromosomes (autosomes); the 23 chromosome pair determines the sex of individual and is composed of either two (x) chromosomes (female) or an (x) and (y) chromosome (male). Genes located on chromosome on it's place or locus.
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Base composition of DNA varies from one species to another. All living things are grouped into three domain: Eukaryotes Prokaryotes and Archaea. In all cells, DNA does not exist free in solution but rather as a protein-coated complex called chromatin http://www.sumanasinc.com/webcontent/animations/content/organelles.html
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Eukaryotic Cell Eukaryotes are generally more advanced than prokaryotes. Eukaryotic cells are found in animals; plants; fungi and protists cell. Cell with a true nucleus, where the genetic material is surrounded by a membrane Eukaryotic genome is more complex than that of prokaryotes and distributed among multiple chromosomes. Eukaryotic DNA is linear. Eukaryotic DNA is complexed with proteins called histones. Numerous membrane-bound organelles. Complex internal structure. Cell division by mitosis.
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Prokaryotic Cell Prokaryotic Cell Unicellular organisms, found in all environments. These include bacteria and archaea. Without a nucleus. no nuclear membrane (genetic material dispersed throughout cytoplasm No membrane-bound organelles Cell contains only one circular DNA molecule contained in the cytoplasm DNA is naked (no histone) Simple internal structure. Cell division by simple binary fission. Archaea are prokaryotes; organisms without nucleus but some aspect of their molecular biology are more similar to those of eukaryotes.
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Timeline Events of Molecular Biology: 1860Mendel – Mendel’s law of inheritance, gene& chromosome 1868Miescher – nuclein, contained an acidic material 1890Weismann - substance in the cell nuclei controls development. 1900Chromosomes shown to contain hereditary information, later shown to be composed of protein & nucleic acids. 1928Griffith’s Transformation Experiment 1944Avery’s Transformation Experiment 1953Hershey-Chase Bacteriophage Experiment 1953Watson & Crick propose double-helix model of DNA 1956Gierer & Schramm/Fraenkel-Conrat & Singer Demonstrate RNA is viral genetic material.
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The law of independent assortment The law of independent segregation The law of dominance Comment: Genes are located on chromosomes
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Called in nuclein since it was from the nucleus Had large amounts of phosphorous and no sulfur so was very different than protein Comment: the two constituents of chromosomes; Proteins & DNA Analytical Tests for C, H,P,O and N “Nuclein”
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