Gram positive and gram negative

Created by

Priyana Sangha

Cards (15)

What do gram negative bacteria not retain?
Gram negative bacteria do not retain the gram stain (crystal violet) when washed with acetone and absolute alcohol because their cell wall has an outer layer
What colour is gram negative bacteria?
The colour of gram negative bacteria is pink/red
What do gram positive bacteria retain?
Gram positive bacteria do retain the gram stain because they think peptidoglycan wall absorbs the stain and they do not have an outer shell
What colour is gram positive bacteria?
The colour of gram positive bacteria is purple/violet
Why does gram positive bacteria turn purple/violet?
This happens because peptidoglycan absorb the stain
What is the 1st step of the gram stain?
Crystal violet - all purple
What is the 2nd step of the gram stain?
Iodine - all purple
What is the 3rd step of the gram stain?
Alcohol - gram positive is purple/gram negative is colourless
What is the 4th step of the gram stain?
Safranin - gram positive is purple/gram negative is red
What gram does penicillin work best on?
Penicillin works best on gram positive bacteria by inhibiting peptidoglycan production, making the cells leaky and fragile
Why is gram negative bacteria more resistant to antibiotics?
Gram negative bacteria are more resistant to antibiotics than gram positive bacteria. This is because gram negative have a cell wall with an outer membrane, which protects them from the antibiotic
Why does penicillin work against this type of bacteria?
Penicillin works against this type of bacteria because it bursts the cell wall
Why does penicillin may not work against other type of bacteria?
Penicillin may not work against other type of bacteria because they might be gram negative and have an extra wall
What is the difference between gram positive and gram negative?
Gram negative bacteria have an outer membrane after their peptidoglycan cell wall
What is a cell wall made out of?
The cell wall is made out of peptidoglycan