Question

Katie wants to make ball-and-stick models of the four macromolecules. She has colored balls for each of the elements in these molecules, including the following.

red: hydrogen
black: carbon
purple: oxygen
green: nitrogen

In which macromolecule will she use the black, red, and purple balls in a ratio of 1:2:1?
carbohydrates
lipids
nucleic acids
proteins

Answer 1

Carbohydrates.

Their general formula is Cn(H2O)n (empirical ratio C:H:O = 1:2:1), whereas lipids have far fewer oxygens, proteins and nucleic acids contain nitrogen (and nucleic acids also contain phosphorus).