cDNA vs. mRNA sequence

[DrHJ]

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Hi, I am confused about writing cDNA and mRNA sequences from a given DNA sequence. For example if the DNA sequence is 3'GCAATCT5' what should be cDNA sequence and what is mRNA sequence? When do we start from 3' end and when from 5' end?
Thanks,

 

[FeralisExtremum]

For 3'GCAATCT5' the complementary mRNA strand would be 5'CGUUAGA3'

cDNA is just complementary DNA that is synthesized from RNA after the introns have been removed. If 5'CGUUAGA5' was your final mRNA product after splicing, then the cDNA sequence for it would be the same as your original DNA: 3'GCAATCT5'. If base pairs were removed, you would have to account for that.

New DNA (and RNA) is always synthesized in the 5' to 3' direction.