Left in one large reconstructed part of cell (9)
I believe the answer is:
organelle
'part of cell' is the definition.
('organelle' is part of 'cell')
'left in one large reconstructed' is the wordplay.
I cannot quite understand how this works, but
'left' could be 'l' (common abbreviation) and 'l' is located in the answer.
'one' could be 'ane' (synonyms) and 'ane' is located in the answer.
'large' could be 'l' (eg in clothes sizes) and 'l' is located in the answer.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Another definition for organelle that I've seen is " Specialised part of a cell".)