( ( ( ( ( A ( water molecule ) ) ( is ( made ( of ( ( ( one ( oxygen atom ) ) and ) ( two ( hydrogen atoms ) ) ) ) ) ) ) and ) ( ( each ( of ( the ( two ( hydrogen atoms ) ) ) ) ) ( can ( ( make ( a ( hydrogen bond ) ) ) ( with ( ( another ( the oxygen ) ) ( belonging ( to ( ( ( another ( water molecule ) ) or ) ( a ( protein molecule ) ) ) ) ) ) ) ) ) ) ) . )
(ROOT (S (S (NP (DT A) (NN water) (NN molecule)) (VP (VBZ is) (VP (VBN made) (PP (IN of) (NP (NP (CD one) (NN oxygen) (NN atom)) (CC and) (NP (CD two) (NN hydrogen) (NNS atoms))))))) (CC and) (S (NP (NP (DT each)) (PP (IN of) (NP (DT the) (CD two) (NN hydrogen) (NNS atoms)))) (VP (MD can) (VP (VB make) (NP (DT a) (NN hydrogen) (NN bond)) (PP (IN with) (NP (NP (DT another) (DT the) (NN oxygen)) (VP (VBG belonging) (PP (TO to) (NP (NP (DT another) (NN water) (NN molecule)) (CC or) (NP (DT a) (NN protein) (NN molecule)))))))))) (. .)))
A water molecule is made of one oxygen atom and two hydrogen atoms and each of the two hydrogen atoms can make a hydrogen bond with another the oxygen belonging to another water molecule or a protein molecule.
(ROOT (S (NP (NP (CD 2) (NN hydrogen)) (, ,) (NP (CD 1) (NN oxygen) (NNS atoms))) (VP (VBP combine) (S (VP (TO to) (VP (VB make) (PRT (RP up)) (NP (NP (DT a) (NN molecule)) (PP (IN of) (NP (NN water)))))))) (. .)))
2 hydrogen, 1 oxygen atoms combine to make up a molecule of water.