What is the primary function of carbohydrates in biological systems?

Carbohydrates primarily serve as a source of energy for living organisms. They are organic compounds made up of carbon, hydrogen, and oxygen, and are categorized into simple sugars (like glucose) and complex carbohydrates (like starch and glycogen). When organisms consume carbohydrates, they are broken down into glucose, which can be utilized immediately for energy or stored for later use.

Moreover, carbohydrates play a critical role in energy transfer within cells. For instance, glucose undergoes cellular respiration, a process that converts this simple sugar into ATP (adenosine triphosphate), which cells use as their energy currency. In addition to providing energy, carbohydrates are involved in other biological functions, such as serving as structural components in plant cell walls (cellulose) and facilitating cell recognition processes.

The other options describe important biological functions but do not address the primary role of carbohydrates. Genetic information storage pertains to nucleic acids like DNA and RNA, catalyzing biochemical reactions is the role of enzymes (which are proteins), and while carbohydrates do contribute to cell membrane structure through glycoproteins and glycolipids, this is not their primary function. Thus, the primary function of carbohydrates in biological systems is indeed energy storage and supply.