Introduction To Microbiology PDF

Lecture 1 Infection and Immunity INI-105 INTRODUCTION TO MICROBIOLOGY Dr. Wafaa Khairy  Microbiology is the science that deals with the study of microorgani...

Lecture 1 Infection and Immunity INI-105 INTRODUCTION TO MICROBIOLOGY Dr. Wafaa Khairy  Microbiology is the science that deals with the study of microorganisms, their activities and their influences on different aspects of life.  Medical microbiology is the study of interactions between human and microorganisms with which they coexist  Microorganisms belong to 5 major groups: bacteria, fungi, protozoa, helminthes and viruses. Taken together the helminthes and protozoa are called parasites.  Viruses which are obligate intracellular parasites are incapable of independent existence. Their sizes vary from 20-400 nm. (are composed of nucleic acid surrounded by protein coat). Viruses either RNA or DNA viruses 1 Lecture 1 Infection and Immunity INI-105 -It infect animal and human (viral infection) - it infect bacteria (bacteriophage)  Prions are described as infectious proteins devoid of nucleic acids. Bacteria belong to the prokaryote kingdom. Fungi, and protozoa are members of eukaryote kingdom  The most outstanding character of eukaryotic cells (eu=true karyotin=nucleus) is a distinct nucleus, surrounded by a membrane that separates it from the other contents of the cell.. They are also have mitochondria and other membrane bound organelles 2  Lecture 1 Infection and Immunity INI-105 Prokaryotic cells (pro=before), on the other hand, do not contain a membrane-bound nucleus. Instead their hereditary material is suspended in a portion of cytoplasm called nucleotide or nuclear region. They are also devoid of mitochondria and other membrane bound organelles Property Eukaryotes Prokaryotes Nuclear membrane present Absent Number of chromosomes >1 1 Chromosome arrangement linear circular Cell membrane sterols present Absent Property Eukaryote Prokaryote Organelles (mitochondria and present Absent chloroplasts) Ribosome size 80S (cytoplasmic) 70S Cell division meiosis and mitosis binary fission Cell wall simple complex Size larger smaller 3