Bacteria Flashcards
What are coccus bacteria?
-Spherical
Cells in a regular chain
Streptococcus mutans
Irregular clumps
Staphylococcus aureus
What are Bacillus bacteria?
-Rod shaped
Cells without recognised grouping
Escherichia coli
Cells in chains
Bacillus anthracis
What are prokaryotes?
- Simple internal organisation
- NO MEMBRANE BOUND NUCLEUS
- No mitochondria
- No Golgi or Endoplasmic Reticulum
What are the two groups of prokaryotes?
-bacteria
-archaea
What kind of bacteria doesn’t have a cell wall?
Mycoplasms
What occurs in the bacterial cell cytoplasm?
Protein synthesis
DNA replication
RNA transcription
(Most) metabolic reactions
What are the functions of the bacterial cell membrane?
-compartmentalisation
-energy generation
-electron transport
-ATP production
-nutrient transport
-DNA replication
-protein secretion
-membrane/wall synthesis
What is the role of the bacterial cell wall?
Without cell walls bacteria cells lose shape and can lyse
Alternatives to a peptidoglycan cell wall
Mycosplasmataceae
What are mycobacteria?
-Rod-shaped, Gram-positive bacteria
-Possess unique lipid-rich cell wall
-Acid-fast (Ziehl-Neelsen stain)
Why is it difficult to view mycobacteria under a microscope?
Myco meaning wax relates to its greasy, lipid rich special wall which makes it resistant to gram stain
This means it doesn’t appear when being observed under a microscope
What are the symptoms of tuberculosis?
-Fever
-Night-time sweating
-Loss of weight
-Persistent cough
-Constant tiredness
-Loss of appetite
What is a flagellum?
a motility apparatus commonly found among motile bacterial species.
substructures include: the filament, the hook, and the basal body.
What are pilli?
Hair-like appendages on cell surface:
2-40 nm in diameter
up to 12 microns in length
can be straight or curved
evenly distributed or present in bundles
can be found on gram-negative and gram positive species but not a universal property
what is the difference between gram positive and gram negative bacteria?
Gram-negative bacteria are surrounded by a thin peptidoglycan cell wall, which itself is surrounded by an outer membrane containing lipopolysaccharide.
Gram-positive bacteria lack an outer membrane but are surrounded by layers of peptidoglycan many times thicker than is found in the Gram-negatives.
