Question

Carbon is a key component of all known life on Earth. Why?

• A. Carbon can bond with carbon to form long chains
• B. All biomolecules contain carbon
• C. Carbon has four valence electrons
• D. Carbon is the only element capable of catenation

Answer 1

Answer: (A), (C)

Carbon has four valence electrons

Carbon is the key component of all life on earth because
1. Complex molecules are made up of carbon bonded with itself, due to its property of catenation.
2. Complex molecules are made up of carbon bonded with other elements, especially oxygen, hydrogen and nitrogen, and carbon can bond with all of these because of its four valence electrons.
3. It is also lightweight and relatively small in size, making it easier for enzymes to manipulate carbon molecules.
But carbon is not the only element capable of catenation. Elements such as silicon, sulfur and boron can also form catenae.