Microbiology Intro Flashcards
Name the domains of life
Bacteria, Archaea, Eukaryota
From which group did Eukaryotes develop?
Archaea
Give the 4 major groups of human pathogens
And are they eukaryotic, prokaryotic, or non-living
Bacteria - prokaryotic
Fungi - eukaryotic
Protozoa - eukaryotic
Viruses - non-living
Name the usual constituents of a bacterial cell
Plasma membrane Cell Wall (Peptidoglycan) Nucleoid Ribosomes Cytoplasm Capsule Flagella, Pili, & Fimbriae
Does the nucleoid have a nuclear membrane
No
Describe the organisation of DNA in a bacterial cell
A single circular chromosome
Plasmids
Describe the basics of how bacterial cells generate energy
- Electrons released from high energy molecules in the cytoplasm
- Pass through a series of electron acceptors to pump protons across the plasma membrane
- Generates a proton gradient (-ve inside, +ve outside)
What is pumped across the plasma membrane during bacterial respiration?
What powers this?
Protons are pumped across
Energy for this comes from electrons
Describe the structure of peptidoglycan
Chains of alternating polysaccharides
These are cross linked by peptide bridges
Give the 2 types of bacterial cell wall
Gram +ve
Gram -ve
Give some similarities of both types of bacterial cell wall
Both act as a barrier
Both provide structure to prevent cell lysis
Both contain peptidoglycan
Describe a gram +ve cell wall
Thick multilayer of peptidoglycan
Where can the cell wall be found in a bacteria?
Under the capsule and above the cell membrane
Describe a gram -ve cell wall
Thin layer of peptidoglycan then Periplasm then Outer membrane then Lipopolysaccharide
Name the space between the outer and cytoplasmic membranes in gram -ve cells
Periplasm
*This is where the peptidoglycan is
Where can lipopolysaccharides be found
And in which type of bacterial cell
All over the the external surface of the outer membrane of gram -ve cells
Which class of drugs target the peptidoglycan
Penicillin
What are lipopolysaccharides?
Glycolipids
What are the roles of lipopolysaccharides?
- Stabilise the outer membrane
- Helps to protect the cell from toxins
- Displays antigens
What are the roles of lipopolysaccharides?
- Stabilise the outer membrane
- Helps to protect the cell from toxins
- Displays antigens
- Incite a strong inflammatory response
What are the subunits of a lipopolysaccharides?
- Lipid
- Core Polysaccharide
- O-chain/antigen
Which are longer fimbriae or pili?
Pili
What type of bacterial cell has pili?
Gram -ve
What type of bacterial cell has fimbriae?
Gram +ve and Gram -ve
