substrates chirality proteins atomic weights chromosomes carbons molecule electron acceptor equilibrium highest energy selectivity oxidation local anesthetic room temperature metabolism alkyne chemical reactions amino acids living organisms dehydration concentration cytosine thymine chemistry sodium organic chemistry phosphate ammonia acids and bases byproducts protons neutrons and electrons activation energy acetone hydrogen peroxide hydrogen bonds solvent cesium chemical reaction single step hydrogen gas covalent bonds glucose cell cycles correlation cis synthesis water molecules ethers electron density atomic mass krebs cycle joules electron pair pyruvate alkene junior chemistry isomer esters atom electrophile molecules presence chemicals dehydration reaction hydrogen intermediates reactants carbon atoms catalysts catalyst ketone alcohol aspirin reagent carbon dioxide dna molecule salicylic acid organic solvents transition state derivatives alkenes alcohols reagents temperatures methanol heat flow nucleophile racemic mixture electrons organic reactions catalytic hydrogenation diels alder reaction acyl atoms protons cells constituents Organic journal article exothermic reaction