Which one of the following statements is incorrect?
Show Hint
Remember the two main biological macromolecules containing nitrogen: Proteins (via amino acids) and Nucleic Acids (via nitrogenous bases). Any statement limiting nitrogen to just one of these is incorrect.
Nitrogen is one of the top five elements found in plants and animals.
Industrial and biological nitrogen fixation require the input of substantial amount of energy.
Nitrogen in organisms is only found in nucleic acids, i.e. DNA and RNA.
Nitrogen is plentiful in the earth's atmosphere in relatively inert forms.
Show Solution
The Correct Option isC
Solution and Explanation
Step 1: Analyze statement A. Living organisms primarily consist of Oxygen, Carbon, Hydrogen, and Nitrogen. This makes the statement correct.
Step 2: Analyze statement B. Breaking the triple bond in atmospheric nitrogen (\(N_2\)) demands significant energy. The Haber-Bosch process and biological nitrogen fixation both require substantial energy. This statement is correct.
Step 3: Analyze statement C. Nitrogen is essential for amino acids (protein building blocks), nitrogenous bases in DNA and RNA, and molecules like ATP and chlorophyll. The statement claiming it's only in nucleic acids is incorrect.
Step 4: Analyze statement D. The atmosphere is roughly 78% nitrogen gas (\(N_2\)). The strong triple bond in \(N_2\) makes it stable and chemically inert, limiting its direct use by most organisms. This statement is correct.
