micropara

• Microbiology


  The study of microbes
• Micro


  Means very small
• Individual microbes can be observed only with the use of various types of microscopes
• Ubiquitous


  Present, appearing everywhere
• Categories of microbes


  • Viruses
  • Bacteria
  • Archaea
  • Protozoa
  • Certain types of algae
  • Fungi
• Prokaryotes


  Cells without a true nucleus and nuclear membrane; called nucleoid
• Eukaryotes


  Cells with a true nucleus enclosed by a nuclear membrane
• Prokaryotes


  • Major group: Bacteria, Archaea
  • Size of cell: Smaller
  • Cell type: Mostly unicellular
  • Nucleus: No true nucleus and nuclear membrane; called nucleoid
  • Cell wall: Peptidoglycan
  • Cell membrane: Lacks sterols
  • Cell division: Binary fission
  • Sexual reproduction: No meiosis; transfer of DNA only
  • Cytoskeleton: Absent
  • Ribosomes: 70S; located in cytoplasm
  • Motility: Flagella (Simple)
• Eukaryotes


  • Major group: Algae, protozoa, fungi, plants, animals, humans
  • Size of cell: Greater than 5 μm in diameter
  • Cell type: Mostly multicellular
  • Nucleus: With true nucleus enclosed by nuclear membrane
  • Cell wall: Present: Cellulose / Chitin
  • Cell membrane: Sterols
  • Cell division: Mitosis
  • Sexual reproduction: Meiosis
  • Cytoskeleton: Present
  • Ribosomes: 80S; located in membranes such as in the endoplasmic reticulum
  • Motility: Flagella (complex)
• Viruses


  • Possess only a single nucleic acid, either DNA or RNA, but never both
  • Extremely small and observed using electron microscopes
  • Considered as obligate intracellular parasites
  • Four categories: Single / double stranded DNA and RNA
• Viroids


  • Single-stranded, covalently closed, circular RNA molecules that exist as base-paired, rodlike structures
  • Cause plant diseases but have not been proven to cause human diseases
• Prions


  • Infectious particles associated with subacute progressive, degenerative diseases of the central nervous system
  • Altered conformations of a normal cellular protein that can automatically form more copies of itself
• Viral multiplication of animal viruses

  1. Attachment

  2. Penetration

  3. Uncoating

  4. Biosynthesis

  5. Assembly

  6. Release
• Bacteria


  • Prokaryotic cells with majority having an outer covering called the cell wall composed mainly of peptidoglycan
  • Possess both DNA and RNA
  • Phenotypic categories: Gram negative with cell wall, Gram positive with cell wall, Acid-fast bacteria, Bacteria without cell wall
• Cell morphology of bacteria

  • Size, shape, and morphologic arrangement are easily observed
  • Size: spheres measuring about 0.2 um in diameter to 10.0 um long spiral-shaped bacteria
  • Shape: round (cocci), rectangular/rod shape (bacilli), curved/spiral shape
• Bacteria


  • The size, shape, and morphologic arrangement of various bacteria are easily observed
  • Size ranges from spheres measuring about 0.2 um in diameter to 10.0 um long spiral-shaped bacteria
  • Shapes include round (cocci), rectangular/rod shape (bacilli), curved/spiral shape
• Algae


  • They are eukaryotic organisms with an outer surface primarily consisting of cellulose
  • Described as plant-like organisms with chlorophyll capable of photosynthesis
  • Do not produce significant disease in humans
• Protozoa


  • Representatives for parasites
  • Eukaryotic cells with an outer surface called a pellicle
  • Exist in two forms: CYSTS and TROPHOZOITES
• Fungi


  • Study of fungi is called mycology
  • Eukaryotic cells with an outer surface composed mainly of chitin
  • Cell membrane made up mostly of ergosterol
  • Possess DNA and RNA with a true nucleus
  • Reproduce via spore production
• Characteristics of Major Protozoa

  • Ciliates
  • Flagellates
  • Sporozoa
• Means of Movement


  • Cilia
  • Pseudopodia (false feet)
  • Flagella
  • Nonmotile except for certain sex cells
• Pathogenic Representatives


  • Balantidium
  • Acantamoeba, Naegleria, Entamoeba
  • Giardia, Trichomonas, Trypanosoma
  • Plasmodium, Toxoplasma, Cryptosporidium, Cyclospora
• Diseases


  • Diarrhea, Keratitis, Meningitis, Amebiasis, STD, Chagas disease, Malaria, Toxoplasmosis, Cryptosporidiosis
• Pathogens


  • Algae: Rare cause of infections, can cause intoxications
  • Bacteria: Anthrax, botulism, cholera, diarrhea, diphtheria, etc.
  • Protozoa: African sleeping sickness, amebic dysentery, giardiasis, etc.
  • Fungi: Allergies, cryptococcosis, histoplasmosis, etc.
  • Viruses: AIDS, chickenpox, common cold, hepatitis, etc.
• Microbiology


  The study of microbes
• Micro


  Means very small
• Individual microbes can be observed only with the use of various types of microscopes
• Ubiquitous


  Present, appearing everywhere
• Categories of microbes


  • Viruses
  • Bacteria
  • Archaea
  • Protozoa
  • Certain types of algae
  • Fungi
• Prokaryotes


  Cells without a true nucleus and nuclear membrane; called nucleoid
• Eukaryotes


  Cells with a true nucleus enclosed by a nuclear membrane
• Characteristics of Prokaryotes


  • Bacteria
  • Archaea
• Characteristics of Eukaryotes


  • Algae
  • Protozoa
  • Fungi
  • Plants
  • Animals
  • Humans
• Prokaryotes


  • Smaller in size
  • Mostly unicellular
  • No true nucleus and nuclear membrane; called nucleoid
  • Cell wall made of peptidoglycan
  • Lacks sterols
  • Cell division through binary fission
  • No meiosis; transfer of DNA only
  • Absent cytoskeleton
  • 70S ribosomes located in cytoplasm
  • Flagella (Simple) for motility
• Eukaryotes


  • Greater than 5 μm in diameter
  • Mostly multicellular
  • True nucleus enclosed by nuclear membrane
  • Cell wall made of cellulose / chitin
  • Sterols present
  • Cell division through mitosis
  • Meiosis for sexual reproduction
  • Cytoskeleton present
  • 80S ribosomes located in membranes such as in the endoplasmic reticulum
  • 70S ribosomes found in organelles such as mitochondria or chloroplast
  • Flagella (complex) for motility
• Viral Multiplication of Animal Viruses

  1. Attachment

  2. Penetration

  3. Uncoating

  4. Biosynthesis

  5. Assembly

  6. Release
• Types of Viruses


  • Single stranded DNA
  • Double stranded DNA
  • Single stranded RNA
  • Double stranded RNA
• Acellular Microbes


  • Viruses
  • Viroids
  • Prions
• Viruses possess only a single nucleic acid, either DNA or RNA, but never both
• Viruses are extremely small. They are observed using electron microscopes and are considered as obligate intracellular parasites