Impact of microbes

• What is the key feature of viruses

  They are non-cellular.
• What are the microbiomes studied in microbiology

  Viruses.

  Prokaryotes

  Eukaryotes
• What are the 3 domains

  Eukaryotes

  Arahcae

  Bacteria
• What are the microscopic eukayotes

  Protists

  Algae

  Fungi
• What are the main features of eukaryotes

  Multicellular with membrane bound organelles
• What are teh features of archae

  They are extremophiles
• Label this cell

  This is a eukaryotic cell.

  A) Nucleus

  B) mitochondria

  C) Chloroplast

  D) Ribosomes

  E) RER

  F) SER

  G) Mitochondria

  H) Golgi apparatus

  I) Cell wall

  J) Cell membrane

  K) cytoplasm

  
• Label the cell

  This is a prokaryotic cell.

  The S-layer is made of proteins or glycoproteins.

  Inclusions are stores of nutrients.

  The capsule layer may be called the slime layer and is used for protection and attachment.

  Pili may also be present and are used for mating.

  Fimbrae may also be present and are used for recognition and/or attachment.

  A) Flagellum

  B) S-layer

  C) Nucloid region

  D) Ribosomes

  E) Inclusions

  F) Capsule

  G) Cell wall

  H) Cell membrane

  
• What are the two functions of the bacterial membrane

  It acts as a barrier but is also selectively permeable.
• Label the bacterial shapes

  X

  A) Coccus

  B) Rod

  C) Spirrlium

  D) vibrio

  E) Hypha

  F) Stalk

  G) Filamentous

  H) Spirochete

  
• What shape is neisseria meningitidis

  Diplococci
• What shape is streptococcus pneumonia

  Stretpococci
• What shape is staphylococcus aureus

  A clump of cocci
• Label this and describe the test.

  This is a gram stain test for bacteria.

  1. Crystal violet in excess then water rinse
  2. Add Iodine to react with crystal violet
  3. Wash with ethanol then water
  4. Counterstain with safranin and water rinse

  A) Gram-negative

  B) Gram-positive

  C) Outer membrane

  D) lipopolysaccharide

  E) Peptidoglycan

  F) Cytoplasmic membrane

  
• Describe the +ve gram stain result

  The thick cell wall traps the crystal violet. This masks the red safranin dye.
• Describe the gram -ve stain result

  The cell wall is not thick enough to trap the crystal violet and so it is easily rinsed by the ethanol. The safarin dye makes the cell appear pink.
• What colour is gram +ve

  Purple or blue
• What colour is the gram -ve

  Pink or red
• Which bacteria is harder to treat

  Gram negative due to the extra lipopolysaccharide membrane surrounding the cell wall.
• Describe the action of cell wall antibiotics

  They prevent cell wall formation.

  They are known as bacteriolytic because lysosomes break the G-M bonds within the cell wall.
• What type of antibiotic is penicillin

  A bacteriolytic which prevents cell wall formation.
• Why can penicillin not be used against archae

  They lack peptidoglycan in the cell wall.
• What is a polar flagella

  when the flagella is at the end of the cell
• What is a monotrichous flagella

  When there is only 1 flagella.
• What is an amphitrichous flagella

  When there is one flagellum at either end fo the cell
• What is a lophotrichous flagella

  When there is a cluster of flagella at one or both ends of the cell
• What is a petrichous flagella

  When the flagella is spread over the surface of the bacteria.
• What type of bacteria make endospores

  Gram positive
• What are the advantages of endospores

  They are produced under unfavourable conditions and so can survive for a very long time.