References Molecular cell biology, 6th Edition, Lodish
Introduction • Definition • Classification • History
Function Genetics Biochemistry Proteins Genes Molecular Biology Molecular Biology • ... is the study of biology at a molecular level. • The field overlaps with other areas of biology, particularly genetics and biochemistry • Molecular biology concerns itself with understanding the interactions between the various systems of a cell, including the interrelationship of DNA, RNA and protein synthesis and learning how these interactions are regulated.
Biochemistry and Genetics • Biochemistry is the study of molecules (e.g. proteins). Biochemists take an organism or cell and dissect it into its molecular components, such as enzymes, lipids and DNA, and reconstitute them in test tubes (in vitro). • Genetics is the study of the effect of genetic differences on organisms. Often this can be inferred by the absence of a normal component (e.g. one gene).
The most important groups of organic molecules: Proteins composed of amino acids Lipids composed of glycerol and fatty acids Carbohydrates: mono-, oligo- and polysaccharides Nucleic acids: DNA, RNAs
Intro into Cell Biology -> All living organisms are made out of cells -> Cells are the smallest living unit Human egg cell + sperm
Organ Organism, Organ, Cell Organism Ulf Schmitz, Introduction to molecular and cell biology
Hierarchical organisation of the structure of living systems organisms organs tissues cells Nucleus, mitochondria, Golgi apparat, etc Ribosomes, chromosomes, cytoskeleton, membranes, etc polysaccharides triacylglycerols nucleic acids proteins monosaccharides phospolipids nucleotides N-containing bases Ribose Fatty acids, glycerol, cholin aminoacids
From Genes to Proteins DNA Gen mRNA Protein Ulf Schmitz, Introduction to molecular and cell biology
Cell (Biological) • Smallest unit of life. • Smallest collection of matter that can live. • What is “life”? Hard to answer... • Order • Reproduction (sexual/asexual) • Growth and development • Energy utilization (metabolism) • Response to environment • Homeostasis • Evolutionary adaptation
Cell Biology 1. A Cell is the smallest unit of life. Every living thing is made up of one or more cells. Human Liver Cells
ARISTOTLE (384 BC – 322 BC) Father of Biology Natural philosopher, identified some of the known living characteristics such as reproduction.
Anton van Leeuwenhoek (1632 – 1723) Helped in the improvement of the microscope First to describe muscles, blood flow in capillaries, spermatozoa, bacteria and protozoans The Men of Biology
Cell Biology History 1675. Anton van Lieuwenhoek first observed living cells in pond water. Paramecium Diatoms
Cells as seen before the cell theory Anton van Leeuwenhoek, XVII. century: algae, bacteria, sperm cells, etc.
Simple Scope: Only One Lens (Advantage = Less Distortion) Leeuenhoek’s Microscope
Robert Hooke first observed cork cells.
Carolus Linnaeus (1707 – 1778) Laid the foundations for the modern scheme of Taxonomy Introduced the use of binomial nomenclature (genus + species)
Henri Dutrochet (1776 – 1847), a Frenchphysician Was credited for the formation of cell biology Discovered cells in plants and actual process of osmosis
Louis Pasteur (1822 – 1895) Confirmed the theory of diseases Introduced the process of pasteurization First to create a vaccine against rabies Disproved the theory of spontaneous generation
فلاسک گردن قویی پاستور برای رد نظریه ی تولید خودبخودی
The cell theoryCell as the central unit of biological organization • Cells are the basic units of life. • All living organisms are made up of cells. • Only living cells can produce new cells. • Matthias Schleiden 1838 Theodor Schwann 1835 • plants are made up of cells animals are made up of cells
German botanist Schleiden: concluded that all plants are made of cells. ONION CELLS Schleiden
German biologist Theodor Schwann stated that all animals are made of cells.
1855. German physician Rudolf Virchow concluded that all cells come from existing cells Mitosis: Cell Division DNA is purple
Rudolf Virchow 1858: • „Every animal appears • as the sum of vital units, • each of which bears in itself • the complete characteristics • of life”
Nobel Prize 1962 James Dewey Watson Harvard University Cambridge, MA, USA Francis Harry Compton Crick Institute of Molecular Biology Cambridge, United Kingdom „for their discoveries concerning the molecular structure of nucleic acids and its significance for information transfer in living material”
Domain Eukaryotes -> Plantae multicellular plants, cellulose cell wall, photosynthesis -> Fungi Chitin cell walls Use organic chemicals for energy Molds and mushrooms are multicellular consisting of masses of mycelia, which are composed of filaments called hyphae -> Protists Protozoa, motile via pseudopods, cilia, or flagella Algae, photosynthetic -> Animalia Multicellular animals, Parasitic flatworms and round worms are called helminthes. Microscopic stages in life cycles
Taxonomy - system for organizing, classifying & naming living things • Domain - Archaea, Bacteria & Eukarya • Kingdom • Phylum or Division • Class • Order • Family • Genus • Species • Strains(and type strain)
BACTERIAL PATHOGENS Neisseria meningitis Intro into Cell Biology Yersinia pestis B. burgdorferi Borrellia -> Lyme disease
BACTERIAL PATHOGENS Intro into Cell Biology Clostridium botulinum. CDC. C. tetani -> tetanus Bacillus anthracis Corynebacterium diphtheriae Staphylococcus aureus
VIRAL PATHOGENS HIV Ebola Smallpox Rabies virus
EUKARYOTIC PATHOGENS Intro into Cell Biology Giardia lamblia –> chronic diarrhea Plasmodium vivax -> Malaria Trichomonas vaginalis – vaginosis in females and urethritis in males.
Tranzitions from non-living towards living: I. Prions: molecules resembling ion channels, causing serious illnesses
Viruses -> are NO living organisms -> parasites Intro into Cell Biology -> Consist of DNA or RNA core -> Core is surrounded by a protein coat -> Coat may be enclosed in a lipid envelope -> Viruses are replicated only when they are in a living host cell -> Not cellular
Cell Theory • All living things are made of one or more cells.
Cell Theory • All living things are composed of one or more cell 2. Cells are the basic unit of structure and function in living things Human skin cell
Cell Theory 3. All cells come from pre-existing cells
Eukaryotic versus Prokaryotic • In general Prokaryotic cells are much simpler in anatomy than the Eukaryotes. • Prokaryotes do not possess organelles. • Prokaryotes do not have nucleus (membrane bound DNA). Nucleoid region: region of the cell with high density of DNA (in Prokaryotes). • Eukaryotes usually consist of more complex DNA (in number and coding, introns/exons later…).