80 S Ribosome 

The ribosome present in eukaryotic cells.

(Prokaryotes have the 70 S ribosome. Antibiotics can exlpoit this difference and act on the 70 S ribosome without affecting the 80 S ribosome.)  

List the steps of Gram staining 

          1.  Crystal Violet

          2.  Gram's Iodine

                          3.  Decolorizer (95% alcohol)

                             4.  Safranin Red (counter stain)

What is the most important step in the Gram stain? 

The decoloring step is key because over or under-decolorizing will produce false results. 

Differences of eukaryotic vs prokaryotic cells 

1.  Presence of cell wall in prokaryotes

• peptidoglycan

         2.  Protein Synthesis:

• Prokaryotes have 70 S ribosomes

• Eukaryotes have 80 S ribosomes

List the stages of the growth curve 

1.  Lag Phase

                    2.  Exponential (Log) Phase

          3.  Stationary Phase

     4.  Death Phase 

During what stage in the growth curve are antibiotics most effective and why? 

Antibiotics that target the cell well work best during the exponential (log) phase of the growth curve.

During this phase much cell wall development is occuring, allowing the anitbiotics to act on inhibiting the cell wall. 

Aerobes 

organisms that are able to grow in the presence of oxygen. 

Anaerobes 

Organisms that cannot grow in the presence of oxygen. 

Facultative 

Organisms that can grow in environments with or without oxygen

(most bacteria are facultative) 

Microaerophilic 

A subclass of the aerobes.  These aerobes can grow in the presence of oxygen but prefer higher concentrations of CO₂.

Aerotolerant 

A subclass of the anaerobes.  These anaerobes can survive in low levels of oxygen, but will not thrive and grow in these conditions. 

Inducible Enzyme System 

Beta-lactamase production is not activated until after exposure to an antibiotic. 

 Constituitive Enzyme System

Organism always produces beta-lactamase even when not targeted by antibiotics. 

Beta-Lactam Ring 

The chemical region of antibiotics containing a nitrogen bonded to a carbonyl carbon.

(beta-lactamases inactivate antibiotics by breaking this ring) 

Beta-Lactamase 

An enzyme produced by bacteria that promotes resistance to antibiotics by breaking the chemical bonds of the antibiotic.