Lecture 15 - How genes makes proteins and cells Flashcards
What is the central dogma of molecular biology?
- Genetic info is stored in DNA as genes
- mRNA copy of a gene is made using DNA as a template (transcription)
- Polypeptide chain is made using mRNA as a template (translation)
What is a gene?
a region of DNA that provides instructions to make an RNA molecule
What do all genes have?
Promoter, Transcribed region
What is the Promoter region?
Region that controls gene expression
What is the transcribed region?
Section of the gene that is copied into mRNA
What does the transcribed region of eukaryotic genes contain?
exons, introns
What are exons?
Are the translated regions of a gene
What are introns?
The untranslated regions
What happens to introns before translation?
They are spliced out of mRNA
What does the transcribed region of Prokaryotic genes lack?
Introns
What ability do Prokaryotes NOT have?
Ability to splice mRNA
What enzyme makes mRNA?
RNA polymerase
How does RNA polymerase make mRNA?
Uses DNA as a template to make mRNA, meaning the mRNA will have the exact same sequence as one of the two DNA strands except U is in place of T
How is mRNA processed before translation?
- Introns removed (spliced out) so that only the protein-coding sequence remains
- Some protective elements are added to the ends of the mRNA to prevent degradation
Where does translation occur in eukaryotes?
mRNA is exported out of the nucleus for translation
How does translation differ for prokaryotes?
since they do not have a nucleus they can transcribe and translate mRNA simultaneously
What does the promoter region contain?
transcription factor binding sites and an RNA polymerase binding site