Pyruvate ($C_3H_4O_3$) is not a carbohydrate — it is a 3-carbon keto acid (the ionized form of pyruvic acid), which is the end product of glycolysis. Carbohydrates follow the general formula $(CH_2O)_n$. Glucose ($C_6H_{12}O_6$), sucrose ($C_{12}H_{22}O_{11}$), and ribose ($C_5H_{10}O_5$) all fit the carbohydrate formula.