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7 Pages

Natural Science
Course Code
NATS 1670
Motti Anafi

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NATS 1670 PART TWO {IMMUNOLOGY] MAY 2012 Immunology-study of all aspects of host defense against infection and of adverse consequences of immune responses Edward Jenner  1976 discovery of the smallpox vaccine  vaccination  Term is still used to describe the inoculation of healthy individuals with weakened or attenuated strains of disease-causing agents to provide protection from disease Robert Koch  Proved that infectious diseases are caused by microorganisms  Four broad categories of disease-causing microorganisms or pathogens o Bacteria o Pathogenic fungi o Viruses o Other relatively large and complex eukaryotic organismsparasites Louis Pasteur  Devised vaccine against cholera in chickens and rabies  Led to search for the mechanism of protection and to the development of the science of immunology Emil von Behring and Shibasaburo Kitasato  Discovered the serum of vaccinated individuals contained substances, antibodies specifically bound to the relevant pathogen Immune Response a response made by the host to defend itself against a pathogen  Innate immunity early phases of the host response to infection depend on innate immunity. A variety of innate resistance mechanisms recognize and respond to the presence of a pathogen.  Present in individuals at all times, does not increase with repeated exposure to a given pathogen, and discriminated between a group of related pathogens  EX. Production of antibodies against a pathogen adaptive immune response, as it occurs during the lifetime of an individual as an adaptation to infection with that pathogen o Lifelong protective immunity to reinfection with the same pathogen Elie Metchnikoff  Immunologist, discovered many microorganisms could be engulfed and digested by phagocytic cellsmacrophages  Cells are available to combat pathogens without requiring prior exposurekey part of the innate immune system  Antibodies are produced only after infection, and are specific for the infecting pathogen  The antibodies present in a give person therefore directly reflect the infections to which he or she has been exposed Both innate immunity and adaptive immune responses depend upon the activities of white blood cells- leukocytes NATS 1670 PART TWO {IMMUNOLOGY] MAY 2012  Innate immunity involved granulocytes and macrophages  Adaptive immune responses depend on lymphocytes, providing the lifelong immunity that can follow exposure to disease or vaccination  Together both systems provide a defense system  Infections are handled by the innate immune system, if the infection cannot be resolved it triggers adaptive immunity, and after overcoming successfully, a lasting immunological memory follows The components of the immune system The cells of the immune system originated in the bone marrow where many may mature. They then migrate to guard the peripheral tissues, circulating in the blood and in the lymphatic system Hematopoietic stem cellsfrom bone marrow  All elements of blood derive from the same progenitor or precursor cells o Red blood cells o Platelets o White blood cells Proteins -proteins are a language based on amino acid NATS 1670 PART TWO {IMMUNOLOGY] MAY 2012 -proteins are the active players in most processes -involved in essentially all sub-cellular and developmental functions in living organisms major classes of proteins: 1. enzymatic: catalysts in biochemical reactions (DNA/RNA polymerases) 2. regulatory: control of gene expression, intercellular signaling (transcription factors) 3. structural: cellular or organismal anatomy Amino Acids Amino Acids are basic building blocks of Proteins. The protein in our cells is built from a repertoire of 20 amino acids. Amino acids are consist of central carbon atom (alpha- carbon), linked to an amino group, a carboxylic acid group, a hydrogen atom and a distinctive R-group (the side chain). Protein Synthesis of Translation Translation: the process of converting information in nucleic acid sequences into protein The information carried by the mRNA (messenger ribonucleic acid) is read and is used to produce a protein. The following must be present in the cytoplasm for translation to occur: 1) Large amounts of free floating amino acids 2) Ribosomal subunits where amino acids are linked together in the proper order to produce the protein 3) Transfer RNA (tRNA) Transfer RNA (tRNA) interpret the mRNA code and link specific base sequences on the mRNA with specific amino acids Attachment sites consist of a base sequence that matches up with a three-base sequence on the mRNA transcript. Each three-base sequence, a codon, matches with a tRNA that carries one particular amino acid Protein Translation Process 1. Recognize and initiate protein building NATS 1670 PART TWO {IMMUNOLOGY] MAY 2012 a. The start sequence of the mRNA transcript – “A, U, and G” is recognized by a corresponding tRNA molecule and the two ribosomal subunits. The ribosomal subunits assemble around them b. Methionine corresponds to the AUG codon, and is the initiator
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