Question

What is the outermost boundary of a prokaryotic cell?

Answer 1

Eubacteria: Capsule (gram negative bacteria) and Cell Wall (gram positive)

Explanation:

Peptidoglycan is a cell wall unique to bacteria that is composed of protein and carbohydrates - most antibiotics target this layer as it is unique to bacteria and leaves the host organism immediately unharmed (long term it could impact helpful bacteria, but that's a different question).

The capsule is a mucous layer found outside the cell wall in some bacteria - this helps the bacteria adhere to surfaces and prevent exposure to environmental factors (such as antibiotics).