Question 2
Which elements are contained in a lipid?
The right answer is the one marked above.
Carbon (C), hydrogen (H) and oxygen (O) — the same three elements as a carbohydrate.
So elements alone cannot tell a lipid from a carbohydrate. What separates them is the ratio: in a carbohydrate, hydrogen to oxygen is exactly 2 : 1, and in a lipid it is always more than that.