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