How many ATPs from a carbohydrate?

Answer 1

Carbohydrates are an important component of a healthy diet. Some main carbs we eat are starch, sucrose, lactose, fructose. All of these sugars are made naturally by plants or animals. All carbs contain carbon, oxygen, and hydrogen and are broken down into the "simplest" sugar called glucose. Glucose is then broken down further (see glycolysis and Krebs cycle) and finally leaves the body as Carbon dioxide and water. In the process of breaking down, a gram of glucose releases 4kcal of energy. In turn, we use this energy to do voluntary activity such as running or typing and involuntary activity such as powering the heart to beat or pumping sodium out of cells.

Glucose (from carbs, of course) is really important because it is the preferred energy source of the brain (it uses 175g of glucose/day) and cells such as red blood cells.