DNA Flashcards
helicase
unzips DNA strands, break H bonds, In DNA replication, enzyme
DNA polymerase
Enzyme that matches DNA nucleotides to a template strand-5´to 3´ only
primase
makes primer for polymerase to do its work, adds a foundation made of RNA
ligase
glues the new DNA together
Step 1 pt.1 Replication:
Helicase comes into DNA and does what
unwinds (unzips) DNA by breaking hydrogen bonds to create a replication bubble
Step 1 pt. 2 Replication:
Primase does what?
comes into the replication bubble and lays a RNA primer to signal start of replication
Step 2 Replication:
DNA Polymerase does what?
DNA Polymerase comes in and begins building bases to to match to the template strand
only 5’-3’
Leading and lagging strand explanation
based on carbon # location
2 strands; leading and lagging
Leading; 5’-3’
Lagging; 3’-5’ strands but works 5’-3’ for DNA Polymerase, it is broken up into sections(oxazaki fragments)
Step 3 of replication:
Ligase?
Polymerase?
ligase removes the primers and replaced RNA with DNA
Polymerase proof reads for errors
Result of replication
2x DNA
semi-conservative; 1/2 new 1/2 old
transcription and translation go through a process called what?
protein synthesis
Transcription location in Eukaryotic cells
Nucleus
then leaves and goes into cytoplasm to be converted into a protein for translation
Transcription location in Prokaryotic cells
Cytoplasm
What does RNA polymerase do? step 1 and 2?
Transcription
-unzips the DNA by breaking the hydrogen bonds
-only able to add more RNA nucleotides 5’-3’
-only coding complementary info to one side (TEMPLATE STRAND)
- New RNA will have the same info as coding strand except T will be U
When does the RNA polymerase stop
End of transcription in Prok.
Step 3 for Euk.
transcription
when it reaches the terminator
Euk. only- last step
What happens?
Transcription
-Cap and tail are added to ends of the pre-RNA
-introns are cut out
- exons get pasted together
-leaves nucleus and goes into cytoplasm for translation
how many amino acids are there
22
how many permutations are there
64
how many codons are amino acids?
How many are stop codons?
61 amino acids
3 stop
What are codons
3 mRNA bases
codes for 1 amino acid
Step 1; Initiation
small ribosomal subunit attaches to the start codon in the mRNA
What is tRNA?
-contains an anti-codon that complimentary to the mRNA codon to which it binds to
-attached to the end is the corresponding amino acid.
Step 2; Elongation
-large subunit attaches (ribosome)
-more tRNA comes
-tRNA exits but leaves amino acids behind-forming the polypeptide chain
step 3; termination
-stop codon encountered
-ribosome detaches and a polypeptide is released
