Bacteria Flashcards
What does Staphylo, Strepto and Diplo refer to
Staphylo= clustered
Strepto= Straight chains
Diplo=Clusters of 2 bacterial cells
Difference bw prokaryotic and eukaryotic ribosome
Pro- 70s (make of 50s and 30s)
16 RNA makes them unique
Euk- 80s (made of 60s and 40s)
What do bacterial cell walls contain
Peptidoglycan
What do Gram positive bacteria have and what makes the cell wall strong
Thick peptidoglycan layer w/ NAM and NAG cross links
What do Gram negative bacteria have
Double plasma membrane with thin cell wall in between with less peptidoglycans
What color will gram positive and negative bacteria turn
positive- purp
neg- pink
What are the 2 toxins released by bacteria
- Exotoxins
2. Endotoxins- refers to lipo poly saccharide which is a major component of gram neg bac
What is lipopolysaccharide composed of
O antigen
Core oligosaccharide
Lipid A
Steps of Gram staining
- Crystal violet binds thick PG layer
- Iodine fixes stain
- Alcohol removes weakly bound CV
- Sadranin added to decolorized bac
What are all bacteria surrounded by (2)
- Capsul made of glycocalyx
2. Slime made of biofilm
What is a biofilm and how is it made
aggregation of microorganisms in which they stick to eachother and also a surface
-start from a single planktonic cell that attaches to a surface and starts producing slime. Overtime more attach and large slime layer is produced (may protect agains antibiotics)
What are fimbriae and pili
fimbriae- bristle appendages that are used to adhere to host cells
Pili- used for bacterial conjugation (sex pilus)
What are secretion systems used for and what type of bacteria are they found on
Found in some gram negative bacteria to inject exotoxins into target cells.
What are the genetics of the bacteria stored in the cell
Nucleoid region and
Extrachromosomal circles called plasmids (not essential for survival)
What happens in binary fission
Bacteria primary reproduce asexualy
no increase in genetic diversity
