( ( ( One gram ) ( of protein ) ) ( ( contains ( four calories ) ) . ) )
(ROOT (S (NP (NP (CD One) (NN gram)) (PP (IN of) (NP (NN protein)))) (VP (VBZ contains) (NP (CD four) (NNS calories))) (. .)))
One gram of protein contains four calories.
(ROOT (S (NP (NP (CD One) (NN gram)) (PP (IN of) (NP (NNS proteins)))) (VP (VBZ provides) (NP (NP (CD four) (NNS calories)) (PP (IN of) (NP (NN energy))))) (. .)))