Central dogma Flashcards
(25 cards)
DNA–> DNA:
DNA–> RNA:
RNA–>Protein:
DNA–>RNA:
Replication
Transcription
Translation
Reverse transcription
In prokaryotes, transcription and translation ….
Can take place simultaneously, but with different complexes doing each.
Eukaryotes _____ their mRNA in a few different ways, while prokaryotes do not.
Modify
In Eukaryotes, what happens between transcription and translation?
mRNA processing: Adding a 5’ cap and a poly-A tail. Also, removal of introns.
In translation, we use a sequence of _____ nucleotides (called a _____) to determine which amino acid to add next to our protein.
three
codon
Each codon can carry the code for:
only one, specific amino acid
What is the start codon?
AUG. It also codes for
methionine, so every protein starts out with methionine.
What are the stop codons?
UAA, UAG, and UGA
In transcription, once the DNA is opened up, ____ _______ proceeds along the DNA, copying one strand.
RNA polymerase
RNA is built off of the _______ strand. The DNA strand that has the same sequenceas the mRNA is called the ______ strand.
Template
sense
Eukaryotes often have a special stretch of DNA
called a ______ ______, about 30 nucleotides upstream
of where transcription will start.
TATA box
What protein do Eukaryotes use to interact with the TATA box?
TBP (TATA Box binding protein)
What is the name of the complex that modifies mRNA?
Spliceosome
Within the spliceosome, what actually does the cutting?
snRNPs
Spliceosomes cut out ________ and leave _______.
Introns
Exons
What are the first two steps of translation?
1-mRNA and small ribosomal subunit join
2- tRNA carrying methionine now joins
When does the large ribosomal subunit join the small one?
AFTER tRNA (carrying Met) joins small subunit
How do tRNAs move through the ribosome?
EPA-
From A, to P, to E
Where is energy spent in the ribosome?
When tRNA binds to A site
To move from P to E site
What is a release factor?
On the stop codon, releases the AA from the ribosome. Costs energy, then the whole complex diassembles.
What is a point mutation?
Where one or a few nucleotides are changed, either a substitution mutation, or a frameshift mutation
What is a substitution mutation?
An incorrect nucleotide (or more) is found in the gene,
but no other changes are made.
What are the three types of substitution mutations?
What happens in them?
1) Silent or neutral: no change to protein
2) Misssense: wrong amino acid added
3) Nonsense: premature stop codon
What is a frameshift mutation?
When nucleotides are added or deleted from an otherwise
correct sequence.
