NUCLEIC ACID CENTRAL DOGMA Flashcards
Characteristics of Replication
Semiconservative
Bidirectional
Semidiscontinuous
High Fidelity
Replication is
DNA - DNA synthesis
Replication occurs during the
S-Phase
Replication requirements
Template (both strands of DNA)
RNA PRimers
Nucleotide monomers (dNTPs)
Enzyme
Replication steps
Initiation
Elongation
Termination
Identify what step of Replication:
Recognition of replication sites
Initiation
Identify what step of Replication:
DNA helicase unwinds the double helix
Initiation
Identify what step of Replication:
Replication fork is stabilized
Initiation
Use of SSBPs (single-stranded binding proteins)
Initiation
Identify what step of Replication:
Adding of nucleotides to the daughter strands
Elongation
What step in replication uses DNA polymerase
Elongation
Identify what step of Replication:
Primase adds an RNA primer
Pol-delta/Pol-epsilon elongates the new strands by adding nucleotides
Elongation
Identify what step of Replication:
Removal of RNA primers and replacement w/ DNA
Termination
Identify what step of Replication:
Joining of okazaki fragments by DNA ligase
Termination
Leading strand
synthesized in the 5’ to 3’ direction
Lagging strand
synthesized in the 5’ to 3’ direction
Characteristics of Transcription
Unidirectional
Lower fidelity
Transcription is
DNA - RNA synthesis
Occurs by demand/Isa-isa
Transcription
Requirements of Transcription
Template strand
RNA POlymerase
Nucleotide monomers (NTPs)
Transcription steps
Initiation
Elongation
Termination
Post-transcriptional processing
Identify what step of Transcription:
RNA Polymerase binds to the promoter region
Initiation
Identify what step of Transcription:
Prepares the mRNA transcript for the cystosolic environment
Post-transcriptional processing
To avoid hazardous post-transcriptional processing you could do
5’ capping
3’ polyadenylation
Splicing
Features of Translation
Universality
Degeneracy
Specificity
Non-overlapping
Translation is
RNA - PROTEIN synthesis
Translation takes place in the
Ribosome
Translation steps
Activation of tRNA
Initiation
Elongation
Termination
Post-translational modification
Sites of the large subunit (Elongation)
A (acceptor)
P (peptidyl transferase)
E (exit)
Site of large subunit where new tRNA enters
A (acceptor)
Site of large subunit where peptide bonds are
P (peptidyl transferase)
Site of large subunit where tRNA (no AA) exist
E (exit)
A change in the base sequence of DNA
Mutation
Alteration of amino acids/base
Frameshift mutation
Due to insertion or deletion
Frameshift mutation
Substitution of bases resulting in a
nonsense codon
Nonsence mutation
Occurs when the codon containing the change base may become a termination codon
Nonsence mutation
Substitution of bases in an amino acid substitution in a synthesized protein
Missense Transition
Codes different amino acids
Missense Transition
GCU - GAU (alanine to aspartate)
Missense Transition
Occur in the absence of any mutation-causing agent
Spontaneous
Codes the same amino acid
Silent transversion
GCU - GCC - alanine
UCA - UCU - serine
Silent transversion
Base substitution caused by tautomeric base-mispairs
Point mutation
Most mutable in point mutations (due to ease of tautomerization)
Cytosine
Point Mutations
Tranversional Mutation
Transitional Mutation
Insertion
Deletion
DNA mutation occurs when a purine replaces pyrimidine, or vice versa
Tranversional Mutation
Purine replaces purine
Transitional mutation
Polycistronic
Prokaryotes
1 gene = may encode several protein
Prokaryotes
1 gene = 1 protein
Eukaryotes
Binds to bacterial RNA polymerase
Rifampicin
Recognition site for 30s sequence
Shine-Dalgarno Sequence
The ability of certain anticodon to pair w/ codons that differ at the third base
Wobble
Concept by which a tRNA can recognize more than one codon for a specific amino acid by allowing movement in the first base of the anticodon
Wobble hypothesis
Intercalate w/ the minor groove of the double helix
Dactinomycin (Actinomycin-D)
Dactinomycin (Actinomycin-D) inhibit what central dogma?
Transcription
Intercalate w/ DNA & causes frameshift mutation
Benzopyrene