"adenylyltransferase" - 1 õppematerjal

TAIMEFÜSIOLOOGIA KORDUSKÜSIMUSED 2012

starch synthesis in the chloroplasts. 86. Miks keskpäeval toimub fotosünteesivates rakkudes ümberlülitus sahharoosi sünteesilt tärklise sünteesile Tärklise süntees vajab ATP-d ja selle ahela tähtsaim ensüüm ADP glükoosi pürofosforülaas on allosteeriliselt aktiveeritav PGA, F6P ja trioosfosfaatide poolt. Plants produce starch by first converting glucose 1-phosphate to ADP-glucose using the enzyme glucose-1-phosphate adenylyltransferase. This step requires energy in the form of ATP. The enzyme starch synthase then adds the ADP-glucose via a 1,4-alpha glycosidic bond to a growing chain of glucose residues, liberating ADP and creating amylose. By contrast, starch synthesis occurs within chloroplasts. The first step is a condensation of glucose-1-phosphate withATP. Starch synthesis requires withdrawal of hexose-P from the mesophyll cellular pool. Using hexose-P for starch synthesis