Module 2: Bacteria

• basic building blocks of the cell:

  • proteins
  • nucleic acids
  • lipids
  • sugars
• membranes maintain barrier and contain cell components
• basic life functions:

  • compartmentalization and metabolism
  • reproduction
  • evolution
  • differentiation
  • communication
  • movement
• microorganisms evolve as populations
• what basic life functions do all microbes share?

  • compartmentalization and metabolism
  • reproduction
  • evolution
• what do you use a light microscope for?

  to see basic cell shape
• what do you use a phase-contrast microscope for?

  to see living specimens
• what do you use a electron microscope for?

  to see at higher magnification
• which microscopes would help determine cell shape?

  light and phase microscopes
• what microscope will show small pili that provide motility?

  scanning electron and confocal microscope
• what microscope will help determine protein structure?

  x-ray crystallography
• how would membrane lipid composition change if temperature decreased?

  increase in unsaturated fatty acids
• 3 components of bacterial cell structure: envelope, cytoplasmic contents, cell membrane
• cytoplasm contains:

  • nucleoid
  • polymerase and ribosomes
  • cytoskeleton
  • inclusions
• nucleoid: highly compacted region of DNA without a membrane

  • some bacteria have membranes
• polymerase and ribosomes function: gene expression
• cytoskeleton: self assembling/disassembling protein filament structures
• MreB: cell shape and movement, found in rod-shaped bacteria
• FtsZ: cell division, found in most bacteria
• inclusions: nutrient storage, compartmentalization (metabolism), movement and orientation
• membranes are fluid: phospholipids in constant lateral motion
• unsaturated fatty acids increase permeability and fluidity (more stable at low temps)
• what are the proteins and energy source in ABC transport?

  • solute binding protein and ATP binding protein
  • ATP hydrolysis provides energy to open channel
• how is DNA compacted into the nucleoid?

  formation of loop domains and supercoiling
• ribosomes are 60% RNA and 40% protein
• proteins (amino acid) have a carboxyl group
• nucleic acids (nucleotides) have a phosphate group
• lipids have a hydrocarbon chain
• sugars/carbohydrates have a ring with hydroxyl groups
• what do passive and facilitated diffusion have in common?

  • don't concentrate against the gradient
  • don't cost energy
• active transport: costs energy to move molecule pump inside cell
• ABC transport is an example of a uniporter
• symporter: uses second molecule in high concentration outside the cell to drive transport
• antiporter: second molecule in high concentration inside the cell moves out to drive transport
• group translocation: system binds solute and modifies it while passing into the cell
• what transport type is not carrier mediated?

  passive diffusion
• what transport type is not specific?

  passive diffusion
• what type of energy does active transport use?

  ATP
• what type of energy does group translocation use?

  phosphate bonds
• what transport type modifies solute during transport?

  group translocation