Gram Staining, Lab Terms, and Microorganisms Flashcards
What is the gram + cell wall made up of ?
thick layer of peptidoglycan
- associated with teichoic acids
Why is staining the cells important ?
ensure we can see all the neccessary cells
Is the cell wall thicker in the Gram + or - ?
gram +
What cell retains the crystal violet ?
gram +
What cells retains the safranin which turns it pink ?
gram -
In the gram staining process what causes the forming of the large molecule ?
the application of the iodine (mordant) to the crystal violet
- 2nd step
What is the purpose of the application of crystal violet ?
to permeate the bacterial cells
In the gram + why does the molecule formed, because of the crystal violet and iodine , not able to exit the cell ?
because the cell wall is so thick
- easy for crystal violet to get in but once joined it can’t get out
What is the gram - cell wall made up of ?
thin layer of peptidoglycan
- has a outer membrane with periplasmic spaces
Why is the crystal violet and iodine molecule able to get out of the Gram - cell ?
because it has a outer membrane with periplasmic spaces
- can escape when decolorized
What happens if you leave the decolorizer on for too long ?
can cause the purple of the gram + to lighten up which we don’t want
What is the primary stain ?
crystal violet
What is the mordent ?
gram’s iodine
What is the decolorizer ?
acetone alcohol
What is the counter stain ?
safranin
What is the purpose of applying the acetone alcohol ?
causes the stain to escape some bacterial cell wall rendering them unstained/colorless
- turns gram - clear
What is the purpose of the safranin ?
adds color to the cells that were decolorized
- colorizes the gram - pink
What is the purpose of the grams iodine ?
binds with the stain inside the cell wall making a larger molecule
Is there periplasmic spaces in both gram + and - ?
- present in all gram - which allows things to move out of gram -
- present in some gram +