Antibiotics Flashcards
What is an antibiotic?
A compound that is able to prevent to growth of microorganisms
How are antibiotics produced?
By cultures of microorganisms after the exponential growth phase = a secondary metabolite
What does the limiting factor of microbial growth impact?
The type of secondary metabolite produced
How can the optimal growth of secondary metabolites be achieved?
By manipulating variables other than limiting factor after the exponential phase
- pH
- Temperature
- Carbon source
When are precursors of desired secondary metabolites added?
After the growth phase otherwise it will halt growth
What was the first antibiotic to be discovered?
Penicillin
What is the most common form of penicillin?
Penicillin G
What happens if you chemically alter penicillin G?
You can produce other types of penicillin
What microorganism produces penicillin?
Penicillium chrysogenum
What is the precursor for penicillin G?
Phenyl acetic acid
How does penicillin effect cells?
Prevents cell wall synthesis
Makes the cell wall permeable and therefore intracellular organelles are not protected
Water enters the cell causing it to burst
What antibiotics prevent the synthesis of proteins?
Tryptomyosin
Why are there few antibiotics that work by affecting membranes?
Because the structure of human and microbial membranes are similar and therefore the antibiotic may harm the host
What antibiotic affects nucleic acid replication?
Rifampicin
Why are antibiotics that affect nucleic acid replication not widely used?
Because they are not particularly selective and therefore may harm the host
