The Central Dogma of Molecular Biology Flashcards
What is the flow of genetic information from DNA to phenotype?
DNA is replicated (requires DNA pol) and then with the help of RNA polymerase transcription occurs - DNA to RNA. The final step in DNA to phenotype would be RNA to protein which is called translation and aminoacyltransferase is the enzyme used.
The general purposes of DNA/RNA/proteins
DNA - can store information
RNA - can transduce DNA messages into protein
Protein - can read into and catalyze reactions as ribozymes
What enzyme is used to go from RNA to DNA
retrotranscriptase
What did Francis Crick state?
that information in DNA is unidirectionally transferred to RNA molecules during transcription and to proteins during translation
RNA can _____ itself
replicated
Ribozyme
catalytic RNA
RNA can be retro transcribed to DNA by…
retrotranscriptase
What enzyme is used to convert DNA to RNA
RNA polymerase
What is the job of RNA pol.
to decode DNA to RNA
What is the difference between a normal prion protein and a disease-causing prion
Normal prion is a phosphatidylinositol - anchored protein that is water-soluble
Disease-causing prion is misfolded and resistant to proteolysis
RNA is made up of…
Pentose ring nitrogenated base, and a phosphate group
Ribonucleotides
consists of the RNA monomers + are linked by covalent phosphodiester bonds to form the RNA polymers
What type of bond is between ribonucleotides
covalent phosphodiester bonds
What makes RNA less structurally stable than DNA?
The nitrogenated bases in a single-stranded RNA do not have a partner to readily form h-bonds with, therefore, RNA is prone to react with other nucleic acids
Where is RNA synthesized
in the nucleus and then transported to the cytoplasm
The 5 types of RNA molecules involved in translation + their function
- mRNA - intermediated that carry genetic information from DNA to ribosomes
- snRNA - structural components of spliceosomes
- tRNA - ADaptors between amino acids + the codons in mRNA
- rRNA - structural and catalytic compounds of ribosomes
- miRNA - short single-stranded RNAs that block expression of complementary mRNAs
What is the different nucleotides found in RNA vs. DNA
RNA has Uracil and DNA has Thymine
Guanosine
is a purine DNA nucleoside used to synthesize the guanosine triphosphate (GTP) by phosphorylation
3 major difference between RNA and DNA
- Single-stranded vs. double
- OH group vs. H
- Uracil vs. Thymine
What is the sense (+) RNA
the sense (+) RNA is complementary to the template strand (DNA)
Overview steps of the replication fork
- Helicases unwind the parental double helix
- Single-strand binding proteins stabilize the unwound parental DNA
- The leading strand is synthesized continuously in the 5’ -> 3’ direction by DNA polymerase
- The lagging strand is synthesized discontinuously. Primase synthesizes short RNA primers which are extended by DNA polymerase to form an Okzazki fragment
- After the RNA primer is replaced by DNA pol. DNA ligase joins the Okazaki fragment to the growing strand
Holoenzyme + its function
Holoenzyme is a catalytically active enzyme that consists of apoenzyme and cofactor
Function - to change substrate into product.
DNA polymerase III holoenzyme
(Pol III HE) is an enzyme that catalyzes the elongation of DNA chains during bacterial chromosomal DNA replication
The purpose of all the holoenzyme subunits
Sigma - initiation of transcription (release after)
Alpha - assembly of the tetrametric core
Beta - Ribonucleotide triphosphate binding site
Beta’ - DNA template binding region
W - chaperone activity (control correct folding of B’)
