making proteins Flashcards
(24 cards)
what is the central dogma?
DNA -> RNA -> Protein
what is transcription?
RNA polymerase using DNA as a template to produce mRNA transcript
what is translation?
a ribosome building a protein molecule from mature mRNA
what is chromatin?
compact DNA in the nucleus
what membranes does the nucleus have?
two - inner and outer
what is the nucleolus?
part of the nucleus that encodes ribosomal RNAs
what are the parts of the nucleus?
nuclear envelope
nucleus
chromatin
nuclear pores
nucleolus
nucleoplasm
what does RNA polymerase do?
catalyzes the chemical reactions that synthesize RNA from a DNA template
what are the main types of RNA molecules and what do they do?
mRNAs - messenger, code for proteins
rRNAs - ribosomal, form basic structure of ribosomes and catalyze protein synthesis
tRNAs - transfer, adaptors between mRNA and amino acids
what are the main types of RNA polymerases and what do they encode?
RNA poly I - rRNA
RNA poly II - mRNA, miRNA, snRNA, and snoRNA
RNA poly III - tRNA and 5s rRNA
what is the process of transcription (basic)?
the DNA strand is separated by the RNA polymerase and builds an RNA strand and the two DNA strands come back together
what initiates transcription?
RNA poly recognizes the TATAAA box to initiate:
- RNA poly II binds to TATA binding proteins
- TFIID (transcription factors) starts the process of transcription(recruits additional transcription factors to construct a large protein complex
where is the TATA box located?
at the promoter (DNA region)
how does mRNA leave the nucleus?
through the nucleur pore complex
what does the nuclear pore complex do?
control movement of mRNA, ribosomes, and proteins (import and export)
how does translation happen?
the ribosome locks together with mRNA inside and walks down, translating each codon into a amino acid and creating a chain
what is the ribosome composed of?
a large catalytic subunit (with active site) and a small subunit (finds RNA and ensures codon/anticodon match)
what does tRNA do in translation?
serves as link between mRNA and chain of amino acids (has the anticodons)
what is the start codon?
methionine
what is the stop codons?
uaa, uag, uga
what stops translation?
translation termination factor (a protein)
what is RNA splicing?
removing introns to leave just the exons (part of the RNA that code for proteins) - happens in nucleus
what does the splicing?
spliceosomes
what does splicing allow for?
multiple proteins being encoded in a single gene