Enzymes work only on a single substrate, in most cases true or false

The correct answer is true

Explanation:

Enzymes bind specific chemical reactants known as substrates, in a specific chemical reaction. Enzymes have a unique cleft called active site that only permits specific substrates to bind to this active site.

Each enzyme has a unique shape that fits the specific substrate. It is like a hand and gloves and their specificity is similar to lock and key as a key fits only in it's a specific lock.

Thus, the correct answer is true.

oxygen = 21% of the atmosphere

nitrogen = 78%

carbon dioxide = 0.1%

argon =0.934%