dna mrna problems?

Question

how does the MRNA transcript differ from the DNA.

Answer 1

DNA is made out of deoxyribonucleotides whereas mRNA is made out of ribonucleotides. The difference is an OH group. DNA bases are A, (adenine) T(thymine), C (cytosine), G (guanine). RNA bases are smiliar... except for the aformentioned lack of an OH group.... and... the fact that in RNA thymine is replaced with U (uracil).
When RNAP (RNA polymerase) makes a transcript of DNA, it uses the coding strand as a template (that's what it reads). The non-coding strand, therefore, has the same sequence as the mRNA template except for the U instead of T. After the RNA polymerase has made an mRNA copy it is processed... a 7-methylguanosine cap is added to the 5' end of the mRNA. Sequences of the mRNA (exons) are spliced out via various splicing mechanisms. A poly adenine tail is also added. Very very very rarely bases in the mRNA are actually edited... So yeah. Messenger RNA, after processing does not totally correspond to the DNA template, the major differences are outlined above (U instead of T, and all the mRNA post processing). I hope this helps. If you have more questions... just ask.
(The person above made a very good comment regarding the single stranded nature of mRNA compared to DNA which is double stranded. The single-stranded nature of mRNA allows it to form various secondary and tertiary spacial structures resulting from sequences of the mRNA complimenting eachother.)

Answer 2

The mRNA can differ with the template DNA depending on the organism. Eukaryotes mostly have genes with intruding segments called introns that are spliced out leaving the coding exons in series. These exons are sometimes edited out in mRNA to produce different proteins from one template. This is called alternative splicing

Alternatively mRNA can be edited so they do not exactly copy their template DNA. This is not the same as alternative splice sites, this is an addition and removal of bases in the mRNA.

The mRNA will be 5' f-MET capped and 3' polyA tailed.

However to be called a problem would mean the RNA polymerase editing function failed and a mutation was introduced by miscopying the template. "It’s commonly accepted that transcription makes less errors than translation, but more errors than DNA replication. Although in vitro RNA polymerase makes one error per ~100000 bases, the rate of mis-transcription in vivo is unknown." says Mikhail Kashlev, Ph.D. His theory is that if RNA polymerase miss-copies at a high rate translation of the erroneous mRNA may lead to the existence of enzymes possessing an altered catalytic activity and producing a disease state.

Answer 3

The mRNA transcript is read from the RNA template, a DNA template can aso be used but the mRNA will have to change the thymine to uracil when it is reading the template. The mRNA shouldnt differ at all from the template it copied because it will just be used to make a new RNA stand. Rna is single stranded also while DNA is double stranded. . . .

if your looking furthur into genetics, there are exons and intros on the mRNA transcript, the intros are useless and get cut of of the mRNA and something (cant remember the name right now) pieces together the exons together to make the mRNA.

Answer 4

mRNA is based on DNA codons. RNA Polymerases 1&3 read DNA sequence from 5' to 3'. Then they put nucleotides together forming immature mRNA as they read from DNA template. There is no T nucleotide in mRNA, and U is used instead. mRNA is the messengar RNA by which DNA sends its functional orders out expressing phenotype.

Answer 5

DNA has the following Base sequences, adenine paired with thymine, and cytosine paired with guanine.
mRNA has uracil intsead of thymine.
when DNA replicates, the double helix shap unwinds and unzips, mRNA molecules come into the nucleus where the DNA pair up with the corresponding base, mRNA then make a sequence, where it leaves the the nucleus.