DNA transcription is the process by which the cell makes an RNA copy of the DNA original.
Essential questions: Why does the cell do this? How does the cell do this?
DNA, deoxyribonucleic acid
the original, kept safe in the nucleus.
mRNA, messenger ribonucleic acid
the copy, which will leave the nucleus & go into the cytoplasm
How does the cell do this?
1. In the nucleus, the DNA gene unzips
2. mRNA nucleotides (C, G, A and U) float in.
3. They join up with their complimentary DNA
4. Completed mRNA molecules now peel off, and moves away.
Why does the cell do this?
Consider the DNA to be like an original blueprint. Very important, and we want it protected. We also might use it more than once.
Consider mRNA to be like a photocopy. We can make as many as we need. And if the copy gets damaged, that’s Ok because we still have the original.
What is the difference between DNA and RNA?
RNA has sugar as part of its backbone, with some oxygen atoms.
DNA has a different sugar as part of its backbone, with 1 less oxygen atom. (that’s why it’s called deoxy)
DNA comes in four shapes: C, G, A and T
Thymine (T) is only found in DNA
RNA comes in four shapes: C, G A and U.
Uracil (U) is only found in RNA
DNA is double-helical, while RNA is single helical.