Which term refers to compounds containing carbon, hydrogen, and oxygen in the approximate ratio C:2H:O, such as sugars, starches, and cellulose, that provide short-term energy?

Which term refers to compounds containing carbon, hydrogen, and oxygen in the approximate ratio C:2H:O, such as sugars, starches, and cellulose, that provide short-term energy?

• A. Carbohydrate
• B. Protein
• C. Lipid
• D. Nucleic acid

Answer: (A)

Carbohydrates are compounds with carbon, hydrogen, and oxygen in roughly a 1:2:1 ratio (often written as CH2O)n. This formula matches sugars like glucose and all the starches and cellulose built from them. Their role in providing short-term energy comes from how easily they are broken down into simple sugars that enter cellular respiration to generate ATP quickly. Polysaccharides such as starch and glycogen store energy for rapid mobilization, though they are less energy-dense and require processing to be used. In contrast, proteins contain nitrogen and serve structural and catalytic roles, lipids store energy more densely and for longer-term use, and nucleic acids carry genetic information. The combination of their typical composition and their ready conversion to usable sugar explains why carbohydrates are the go-to short-term energy source.

Carbohydrates are compounds with carbon, hydrogen, and oxygen in roughly a 1:2:1 ratio (often written as CH2O)n. This formula matches sugars like glucose and all the starches and cellulose built from them. Their role in providing short-term energy comes from how easily they are broken down into simple sugars that enter cellular respiration to generate ATP quickly. Polysaccharides such as starch and glycogen store energy for rapid mobilization, though they are less energy-dense and require processing to be used. In contrast, proteins contain nitrogen and serve structural and catalytic roles, lipids store energy more densely and for longer-term use, and nucleic acids carry genetic information. The combination of their typical composition and their ready conversion to usable sugar explains why carbohydrates are the go-to short-term energy source.