Presentation on theme: "Molecular Biology Department of Medical Laboratory Technology"— Presentation transcript:
1 Molecular Biology Department of Medical Laboratory Technology (MLMB-201)Department of Medical Laboratory TechnologyFaculty of Allied Medical ScienceLecturer:Dr. Mohamed Salah El-Din
2 Intended Learning Outcomes (ILO’s): Molecular biology course provides an overview of the molecular basis to cell structure and function.This course focuses on the structure, biosynthesis and function of DNA and RNA on the molecular level and how these interact among themselves and with proteins. Molecular biology techniques are essential for modern biological and medical research. This course will give you an introduction to DNA and RNA standard techniques.Student will have basic knowledge of:Cell organization.DNA structure and function.DNA Extraction.RNA structure and function.RNA Extraction.Gene expression and protein biosynthesis.Agarose gel electrophoresis for DNA/RNA; and SDS-PAGE for protein.Polymerase Chain Reaction (PCR) – Theory, Types, Application.Gene library and screeningDNA sequencing
4 CellsFundamental working units of every living system.Every organism is composed of one of tworadically different types of cells:prokaryotic cells oreukaryotic cells.Prokaryotes and Eukaryotes are descended from the same primitive cell.All extant prokaryotic and eukaryotic cells are the result of a total of 3.5 billion years of evolution.
5 Cells 70% water 7% small molecules 23% macromolecules salts Lipids Chemical composition-by weight70% water7% small moleculessaltsLipidsamino acidsnucleotides23% macromoleculesProteinsPolysaccharideslipidsbiochemical (metabolic) pathwaystranslation of mRNA into proteins
6 Life begins with CellA cell is a smallest structural unit of an organism that is capable of independent functioningAll cells have some common features
7 All Cells have common Cycles Born, eat, replicate, and die
8 Prokaryotes and Eukaryotes According to the most recent evidence, there are three main branches to the tree of life.Prokaryotes include Archaea (“ancient ones”) and bacteria.Eukaryotes are kingdom Eukarya and includes plants, animals, fungi and certain algae.
9 Prokaryotes and Eukaryotes, continued Single cellSingle or multi cellNo nucleusNucleusNo organellesOrganellesOne piece of circular DNAChromosomesNo mRNA post transcriptional modificationExons/Introns splicing
11 ProkaryotesProkaryotes are the most abundant organisms on earth. (bacteria and blue-green algae)A prokaryotic cell dose not contain a membrane-bound nucleus.Size from 0.1 to 10 μm
12 Three basic shapes Spherical(cocci) Rodlike(bacilli) Helically coiled( spirilla)They fall into two groups:the eubacteria and the archaebacteria.
13 The eubacteria Gram-positive Gram-negative Cyanobacteria (cyano-bacteria)in soil,water and living in or on larger organisms
14 The archaebacteria Sulfur bacteria Methanogens（methane） They grow in unusual environments:salt brines,hot acid springs,in the ocean depths
15 Cell structureEach prokaryotic cell is surrounded by a plasma membrane.The cell has no subcellular organelles,only infoldings of the plasma membrane called mesosomes.The deoxyribonucleic aid (DNA) is condensed within the cytosol to form the nucleoid.Some prokaryotes have tall-like flagella.
17 Bacterial cell wallsThe peptidoglycan (protein and oligosacca-ride) cell wall protects the prokaryotic cell from mechanical and osmotic pressure.A Gram-positive bacterium has a thick cell wall surrounding the plasma membrane,whereas Gram-negative bacteria have a thinner cell wall and outer membrane,between which is the periplasmic space.
33 Some Terminology Genome: an organism’s genetic material Gene: a discrete units of hereditary information located on the chromosomes and consisting of DNA.Genotype: The genetic makeup of an organismPhenotype: the physical expressed traits of an organismNucleic acid: Biological molecules(RNA and DNA) that allow organisms to reproduce;
34 The genome is an organism’s complete set of DNA. More TerminologyThe genome is an organism’s complete set of DNA.a bacteria contains about 600,000 DNA base pairshuman and mouse genomes have some 3 billion.human genome has 24 distinct chromosomes.Each chromosome contains many genes.Genebasic physical and functional units of heredity.specific sequences of DNA bases that encode instructions on how to make proteins.ProteinsMake up the cellular structurelarge, complex molecules made up of smaller subunits called amino acids.
35 All Life depends on 3 critical molecules DNAsHold information on how cell worksRNAsAct to transfer short pieces of information to different parts of cellProvide templates to synthesize into proteinProteinsForm enzymes that send signals to other cells and regulate gene activityForm body’s major components (e.g. hair, skin, etc.)
36 Assignment:As a part of the semester activity, one student is selected every week to prepare a short seminar about his/her point of interest in one of the lecture topics. That to be discussed and evaluated during the next lecture.