14.2 polypeptide synthesis - transcription and splicing

Pregunta	Respuesta
what is the basic process of manufacturing proteins?	1) DNA gives instructions in nucleotides and their bases 2) complementary section of part of this is made = pre-mRNA (transcription) 3) pre-mRNA is spliced to form mRNA 4) mRNA = template for complementary tRNA to attach a.a. (translation)
what is transcription?	the process of making pre-mRNA using part of the DNA as a template
what is the 1st stage in the process of transcription?	1. enzyme DNA helicase breaks hydrogen bonds between bases at certain point. this unravels the DNA.
what is the 2nd stage in the process of transcription?	2. enzyme RNA polymerase moves along one of the strands causing nucleotides on this strand to join with individual complementary nucleotides from the pool in the nucleus
what is the 3rd stage in the process of transcription?	exposed bases pair with complementary bases, but Adenine doesn't bind with Thymine now, it binds with Uracil
what is the 4th stage of transcription?	4. as the RNA polymerase adds nucleotides to build pre-mRNA, the DNA strands rejoin behind it so only about 12 bases are exposed at a time
what is the final stage in transcription?	when RNA polymerase reaches a stop codon, it detaches.
how is the pre-mRNA molecule modified?	it is spliced to remove useless introns, so it is just left with exons, making it mRNA

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	Creado por Charlotte Hewson hace más de 8 años