Given a text passage, come up with an appropriate title for it. The title should accurately represent what the main focus of the passage is. The title of a passage may be present in the first few sentences of the passage and/or be referred to multiple times in the passage. The title should be 1-5 words long.
One example is below.
Q: The Beatles ' rooftop concert was the final public performance of the English rock band the Beatles . On 30 January 1969 , the band , with keyboardist Billy Preston , surprised a central London office and fashion district with an impromptu concert from the roof of the headquarters of the band 's multimedia corporation Apple Corps at 3 Savile Row . In a 42 - minute set , the Beatles were heard playing nine takes of five songs before the Metropolitan Police Service asked them to reduce the volume . Footage from the performance was later used in the 1970 documentary film Let It Be .

A: The Beatles' rooftop concert
Rationale: 'The answer given is correct because it is an appropriate title as it is the main subject of the passage.
Q: Peptidoglycan , also known as murein , is a polymer consisting of sugars and amino acids that forms a mesh - like layer outside the plasma membrane of most bacteria , forming the cell wall . The sugar component consists of alternating residues of - ( 1 , 4 ) linked N - acetylglucosamine ( NAG ) and N - acetylmuramic acid ( NAM ) . Attached to the N - acetylmuramic acid is a peptide chain of three to five amino acids . The peptide chain can be cross-linked to the peptide chain of another strand forming the 3D mesh - like layer . Peptidoglycan serves a structural role in the bacterial cell wall , giving structural strength , as well as counteracting the osmotic pressure of the cytoplasm . A common misconception is that peptidoglycan gives the cell its shape ; however , whereas peptidoglycan helps maintain the structural strength of the cell , it is actually the MreB protein that facilitates cell shape . Peptidoglycan is also involved in binary fission during bacterial cell reproduction .
A:
Peptidoglycan