Question

Nitrate Assimilation. Could someone describe this diagram to me in words? (post is below)

Answer 1

Here is diagram, cheers!

Answer 2

In the cytoplasm NadPH reduces Flavin adeninenucleotide(FAD) which passes along the elctrons to intermediate cytochrome and then to Molbdenum cofactor domain where it oxidises Nitrate to nitite and forms hydroxide ( this hydroxide then gets converted to water and gets relased) .The nitrite now in the chloroplast gets reacted on by Nitrite Reductase . Nitriate reductase has 2 redox centers , one of which a siro heme center acts as the site where nitrite binds to the ennzyme , it also has iron -sulphur center ( I am not sureof its function) , and a Nterminal domain which binds to ferridoxin . Ferridoxin gets reduced by the electron from photosystem I and its passes along the 6 electron to siro heme where it converts nitrite to ammonia. In the roots NADPH from the oxidative pentose phosphate pathway reduces a ferridoxin like ptn which binds to Nitrite reductase and helps in converting nitrite to ammonia.

Answer 3

Thanks for the great answer :)

Answer 4

You are welcome , checkout the structures of Nitate and nitrite reductase enzymes , they give a more detailed pic of how these reactions happen , Eg :- the nitrite to ammonia by NiR is thought to be a 2- 3 step sreaction, it kind of gives a better understanding of how the enzymes and their components work together to make this possibile