Question

what would most likely occur if you applied alcohol for only one second?
a) the gram - negative bacteria would decolorize, while the more robust gram - positive bacteria would remain unaffected and retain its purple stain
b) gram - negative bacteria would not decolorize like it should, and all bacteria would therefore remain purple (gram - positive)

Explanation:

In Gram - staining, alcohol is used as a decolorizing agent. Gram - negative bacteria have a thin peptidoglycan layer and an outer membrane. The decolorization step (usually with alcohol for about 20 - 30 seconds) is crucial for removing the crystal violet - iodine complex from Gram - negative bacteria. If alcohol is applied for only one second, it is not sufficient to effectively decolorize Gram - negative bacteria. Gram - positive bacteria have a thick peptidoglycan layer which traps the crystal violet - iodine complex well, and even with a very short alcohol treatment, they retain the purple stain. Gram - negative bacteria, due to insufficient decolorization, would also retain the stain (as the decolorization step is not properly carried out), so all bacteria would appear purple (like Gram - positive).

Answer:

b) Gram - negative bacteria would not decolorize like it should, and all bacteria would therefore remain purple (Gram - positive)