plastocyanin
/ˌplastə(ʊ)ˈsʌɪənɪn/Biochemistry
noun
A blue copper-containing protein (differing slightly from species to species) which is found in the chloroplasts of green plants and in certain bacteria, and is involved in electron transfer during photosynthesis.
Origin
1960s. From plast- + -o- + cyanin.