Introduction to Bacteria

  • Created by: Ro-Po 17
  • Created on: 21-07-18 12:43

Introduction to Bacteria


  • Describe the basic structure of bacteria
  • Describe basic functions of different structures
  • Describe and apply basic concepts of taxonomy

Bacteria are small, rate at which nutrients and waste enter and leave the cell = inversly proportional to cell size

  • Higher growth rates
  • Faster evolution
  • Adapt and exploit new environments

Basic Structure of Prokaryotic cell

  • Cell wall = petidoglycan
    + flagella, pili etc. Provide ridgidity
  • Cell/Plasma membrane = phospholipid bilayer
    Regulates passage in/out bacteria via pore and channels
  • Cytoplasm
    DNA, RNA, Enzymes, Regulatory proteins, Protein synthesis machinery
  • Nuclear region
    No true nucleus 

Cell Wall
DIvides bacteria into 2 main groups
- Gram -- = doesn't tuen purple in crystal violet. then use safranin/carbol fuchsin = Pink stained
- Gram + = turn purple in crystal violet

CW = largely Peptidoglycan
- Polysaccharide backbone + NAG and NAM with cross-linked peptides (short-chain Animo Acids)
- These AAs provide rigid structure
- Enzymes involved in forming crosslinks = targets of antibiotics e.g penecillin

(Comparison in other resource)
Basically, Gram -- has an outer membrane whereas Gram+ don't.

Gram -- Outer Cell Membrane
= permeable lipid bilayer containing phospholipids and LPS (lipopolysaccharide)
Main role as protection, in…


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