Basthansidn

• EUKARYOTIC PLASMAMEMBRANE

  Contain sterols, which help resist rupture
• Mycoplasma are the only prokaryotes

  Whohavesterols
• 1. Allows the ability of endocytosis, where the plasma membrane surrounds a molecule & engulfs it
• 1. Contains carbohydrates that serve as receptors for cell-to cell interactions
• EUKARYOTIC FLAGELLA & CILIA

  • Projections of the cytoplasm used for locomotion
• • If one or few and longer than the cell=flagella
• If multiple but short extensions = cilia
• • Anchored to the plasma membrane by basal body
• • Consist of 9 pairs of microtubules (protein tubes) arranged in a 9+2 array
• prokaryotic flagellum that rotates to propel, the eukaryotic flagellum moves in a wave-like manner
• theory of biogenesis

  claims that living cells can arise only from preexisting living cells
• GERM THEORY OF DISEASE

  considers the possibility that microorganisms might have similar relationships with plants and animals - that microorganisms or "germs" caused disease.
• MAGIC BULLET

  • After establishing the relationship between microorganisms & disease, the next focus was to look for substances that could destroy pathogenic microorganisms.
• • Treatment of disease through the use of chemical substances is called chemotherapy.
• Chemotherapy

  • Term commonly used to describe medications used to treat cancer.
• Chemo=chemical

  therapy=treatment
• Antibiotics

  Chemicals produced naturally by bacteria/fungi to act against other microorganisms
• • SYNTHETIC DRUGS
  • Chemotherapeutic agents prepared from chemicals in the laboratory
• CELL THEORY

  "ALL LIVING ORGANISMS ARE

  COMPOSED OF CELLS"
• • Spontaneous Generation-used flasks with broth
• BACTERIA

  Single-celled prokaryotic organisms enclosed in a cell wall made of peptidoglycan, reproduce through binary fission & use organic chemicals for nutrition
• Archaea

  Prokaryotic organisms similar to bacteria but lack peptidoglycan, and often found in extreme environments (heat, salt, and methane)
• Fungi


  Eukaryotic organisms with cell wall made of chitin; includes both unicellular (e.g.yeast, molds) & multicellular forms (e.g.mushrooms)
• Protozoa

  unicellular eukaryotic microbes with features for locomotion (e.g. pseudopods in amoebae) and live either freely or acts as parasites)
• VIRUSES

  Acellular microbes composed of a core of DNA/RNA with protein coat; obligate intracellular parasites - only divide when inside live organism
• Vaccination

  • A preventive procedure involving the administration of a small amount of live or inactivated microorganism to stimulate immunity.
• Branches of microbiology


  Bacteriology-bacteria

  Mycology-fungi

  Parasitology-helminths/anthropods(microscopic)

  virology-viruses
• Microbes and human welfare

  recycling vital elements

  recycling water

  removal of pollutants

  pest control
• Biotechnology

  refers to the commercial use of microorganisms to produce some common foods and chemicals.
• Recombinant DNA technology

  involves the formation of new DNA molecules (rDNA) formed by methods of genetic recombination (usually from different organisms).
• NORMAL MICROBIOTA

  • Refers to the variety of microorganisms found inside and on our body.
  • These microbes do no harm, and in some cases benefit us.
  • Prevents overgrowth of harmful microorganisms
  • Production of vitamin K and some B vitamins
• GLYCOCALYX

  • "sticky" coating made up of polysaccharide surrounding the cell membranes.
  • Serves as a glue that holds cells in place such as those in biofilms.
• FLAGELLA

  Long filamentous appendages that propel bacteria and flagella has three basic parts:

  • Filament - long outer portion
  • Hook
  • Basal body
• AXIAL FILAMENTS(ENDOFLAGELLA)

  • Bundles of fibrils that arise at the ends of the cell beneath an outer sheath and spiral around it.
  • Present in spirochetes
• FIMBRIAE & PILI

  • Hair-like appendages used for attachment and transfer of DNA to another bacterium.
• CELL WALL

  • Semi rigid structure enclosing the cell, and is responsible for cell shape.
  • Surrounds the underlying plasma membrane and protects the cell from adverse changes in the outside environment.
• GRAM POSITIVE CELL WALLS

  • Cell wall consists of many layers of peptidoglycan, forming a thick, rigid structure.
  • Contains Teichoic acids
  • Consists primarily of an alcohol and phosphate.
• GRAM NEGATIVE CELL WALLS

  • Consist of one or a few layers of peptidoglycan and an outer membrane, and no teichoic acids.
  • Fewer peptidoglycan = more susceptible to breakage
• GRAM STAINING

  Staining method using the dye crystal violet to distinguish gram-positive &gram-negative bacteria.

  • Crystal violet stains both Gram (+) & Gram (-)
  • Mordant (lodine) is then added to form large crystals with the dye.
  • Alcohol is then added to have differing effects: - Gram (+): dehydrates peptidoglycan so violet dye stays- Gram (-): dissolves outer membrane so violet dye leaks
  • Safranin (red) dye is added last as a counterstain to stain Gram - bacteria
• ATYPICAL CELL WALLS

  • Absent cell walls
  • Mycoplasma have no cell walls but cell. membrane contains(sterols that protect the cell from rupture
  • Archaebacteria either lack walls or have unusual walls