Transcription
Which organelles are necessary for protein synthesis?
Ribosomes
The DNA must communicate with the ribosomes to control the production of proteins. How does it do so?
By producing a code that is carried from the nucleus to the cytoplasm by RNA. Transcription is the synthesis of RNA using the base sequence in DNA as a template.
What is the function of RNA polymerase?
Seperates the two DNA strands, also allows the base pairing of the RNA nucleoides along the DNA template/anti-sense strand.
What are the sections of DNA involved in transcrition?
Promoter, Transcription unit, Terminator
The _________ for a gene determines which DNA strand will be the template strand. It is a short sequence of bases that is not transcribed.
Promoter region
What are transcription factors?
Proteins that play a role in the regulation of the transcription process. They determine which genes are active in each cell of an organism's body. In eukaryotic cells, they first allow the attachment of RNA polymerase to the promoter region so that transcription can begin.
Do transcription factors always activate transcription?
No, some do but others prevent or repress transcription. The expression of many genes is controlled by multiple transcripion factors, in which case often a specific combination of these factors is needed for transcription to take place.
As RNA polymerase moves along the DNA template strand, what happens?
RNA nucleotides that exist in the nucleus float into place by complementary base pairing. These pairs are the same as in DNA but adenine is paired with uracil.
The streches of non-coding DNA in eukaryotic cells is called ______.
Introns
As a complete region of a DNA molecule is transcribed to form mRNA, the first RNA formed is called the _________. It contains both _____ and ______. The _____ are removed to make a functional mRNA strand. This process is called ______.
pre-mRNA or primary RNA transcript, exons, introns, introns, splicing
Spliceosomes are made of multiple _____________ and ______. They remove ______ from the primary mRNA. When the _____ are removed, the _____ may be rearranged, causing the production of different proteins. This increases the number of possible proteins that can be produced by one gene. The spliceosomes then help join the _________.
small nuclear RNAs, proteins, introns, introns, exons, remaining exons
On the 5' end of the final mRNA transcript is a cap made of a modified _________ nucleotide with ____ phosphates. At the other end, the 3' end, is a _________ composed of 50-250 ______nucleotides. The cap and _________ stabilize the mature mRNA, protecting it from degradation in the cytoplasm, and enhance the translation process that occurs at the ribosome.
Guanine, 3, polyAtail, adenine