How the Gram stain works

How do gram positive cells prevent crystal violet from being washed out? (1)

Alcohol (destainer/decolorizer) dehydrated the thick peptidoglycan layer resulting in them to become a tight mesh-like layer that doesnt let the crystal violet to go out even thoughthe membrane was disrupted.

Why does the primary stain (crystal violet) get washed out in gram negative cells? (1)

The 2 membranes are damaged and the peptidoglycan layer is too thin to stop the crystal violet from being thrown out.

What makes peptidoglycan so special? (1)

Nothing in humans resemble it

Many antibiotics can degrade peptidoglycan. What is an example of an antibiotic that works against peptidoglycan and how? (1)

penicillin (inhibits production of peptidoglycan

What of our natural defences can degrade peptidoglycan, and where is it found on our body?

• Lysozyme (found in tears, sweat, saliva, mucous