The collagen triple helix structure is not found in:
|C||Lumen of endoplasmic reticulum|
1. Extracellular matrix contains three major classes of biomolecules.:
A. Structural proteins → collagen, elastin
B. Specialized protein → fibrillin, fibronectin, and laminin; and
2. Collagen, the major component of most connective tissues, constitutes approximately 25% of the protein of animals. It provides on extra cellular framework for all metazoan animals and exists in virtually every animal tissues. There are about 19 distinct types.
3. Collagens have Triple helix structure
4. Synthesis and post translational modification of the collagen: -
Synthesized in ribosome’s as prepro-collagen→Directed in vesicular space of endoplasmic reticulum → where hydroxylation and glycosylation as well as formation of disulfide bonds take place → then secreted extracellularly by way of the Golgi apparatus
Now, conclusion - As you see, that the process of collagen synthesis and modification takes place via
ribosomes to vesicles to endoplasmic reticulum to Golgi apparatus then finally secreted out side cells.
That is why I select the answer cytoplasm, because collagen-synthesis and modification do not takes
place in cytoplasm, therefore, definitely it absent in cytoplasm.