5 Questions
What is the reason behind gram-positive bacteria appearing purple after the Gram stain test?
They retain the crystal violet stain due to their thick peptidoglycan layer
Why do gram-negative bacteria appear red or pink after the Gram stain test?
They retain the counterstain (safranin or fuchsine) and appear red or pink
What effect does alcohol have on gram-negative bacteria during the decolorization stage of the Gram stain test?
It degrades the outer membrane, making the cell wall more porous
What is the main difference in cell wall structure between gram-positive and gram-negative bacteria?
Thickness of peptidoglycan layer and presence of an outer membrane
Why are gram-positive bacteria more receptive to certain cell wall–targeting antibiotics than gram-negative bacteria?
Due to the absence of an outer membrane
Test your knowledge of gram-positive bacteria with this quiz. Learn about the characteristics and classification of gram-positive bacteria based on their cell wall composition and the Gram stain test.
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