( Carbohydrates ( ( ( ( contain ( ( four calories ) ( per gram ) ) ) and ) ( is ( ( the ( energy source ) ) ( ( preferred ( by ( ( muscle and ) ( the brain ) ) ) ) ( during ( active exercise ) ) ) ) ) ) . ) )
(ROOT (S (NP (NNS Carbohydrates)) (VP (VP (VBP contain) (NP (NP (CD four) (NNS calories)) (PP (IN per) (NP (NN gram))))) (CC and) (VP (VBZ is) (NP (NP (DT the) (NN energy) (NN source)) (VP (VBN preferred) (PP (IN by) (NP (NP (NN muscle)) (CC and) (NP (DT the) (NN brain)))) (PP (IN during) (NP (JJ active) (NN exercise))))))) (. .)))
Carbohydrates contain four calories per gram and is the energy source preferred by muscle and the brain during active exercise.
(ROOT (S (NP (NP (CD One) (NN gram)) (PP (IN of) (NP (NNS carbohydrates)))) (VP (VBZ provides) (NP (NP (CD four) (NNS calories)) (PP (IN of) (NP (NN energy))))) (. .)))