Biochemistry question

[dentheartthrob]

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which one should I follow.

from kaplan:
glycosylation of collagen sythesis occurs in the lumen of the the R.E.R or...

from USMLE first AID:
it occurs in the golgi complex

 

[DrTacoElf]

Ok this is very difficult to find a sure answer. But read this.

The triple helices of procollagen form before they move from the cisternae of the rough ER to the Golgi apparatus, indicating that the hydroxylysyl glycosylations are completed within the cisternae of rough ER (Kivirikko & Myllylä 1979, see Figure 6). Figure 6. Schematic representation of the events in collagen biosynthesis that occur within the cisternae of the rough ER. The propeptide is removed during the translocation across the membrane and hydroxylation of lysyl residues and glycosylation of hydroxylysyl residues are initiated while the polypeptide chains are still being assembled on the ribosomes. The reactions continue after the synthesis of complete pro α-chains until the triple helix is formed. LH: lysyl hydroxylase; GT: hydroxylysyl galactosyltransferase; GGT: galactosylhydroxylysyl glucosyltransferase; Gal: galactose; Glu: glucose (Modified from Kivirikko & Myllylä 1984 with permission of Elsevier Science).




http://herkules.oulu.fi/isbn9514267990/html/x566.html

The big debate comes from the fact that the enzymes responsible are found in the ER and golgi.