Molecular Biology (W12) Flashcards
define penetrance and expressivity
penetrance : % of individuals that express the phenotype
expressivity : degree to which the trait is expressed
what is the difference between a ribose and deoxyribose sugar
ribose: OH group on carbon 2
deoxyribose : H group on carbon 2
how many hydrogen bonds form between each of the base pairs
A + T form 2 H bonds
C + G form 3 H bonds
what is the direction of a ssDNA
5’ to 3’
what end of a growing strand of DNA are the free bases added to
3’ end
(added to 3’ end so moving away from 5’ end)
how does the free nucleotide attach to the strand of DNA
2 of the phosphate molecules get cleavered off and the remaining one is free to bond with the OH group on the Carbon 3 to form a phosphodiester bond.
what are the similarities (2) and differences (2) between DNA replication and transcription
- they both require a template strand
- they both work in a 5’ to 3’ direction
differences - transcription has RNA polymerase whereas DNA replication has DNA polymerase
- DNA replication requires a primer whereas transcription does not need a primer
what is the difference between the coding sequences of DNA in prokaryotic and eukaryotic cells
in prokaryotic the whole section is coding
whereas Eukaryotic cells it has section of coding (Exons) and non coding (Introns)
what processing to the RNA molecule must be done before it moves into the cytoplasm
it must have a 5’ cap put on the 5’ end and a poly A tail on the 3’ end and have the introns spliced out
what are the 3 steps of PCR and the temps they occur at
Denaturing: 95˚
Annealing: 50 - 75˚
Extension: 72˚
what 5 things are needed for a PCR
- DNA polymerase
- template strand
-primer - dNTPs
- Mg2+
what does VNTR stand for and what does it mean
Variable Number Tandem Repeats / Microsatellites
where a short sequence of DNA is repeated (with a variable length)
what is a potential problem using prokaryotic cells to make a eukaryotic product and how can we solve it
- prokaryotic cells dont have introns and so cant remove it from our DNA
- a solution would be making complementary DNA from a mRNA strand that already has it removed
what 2 types of dye are required in a gel electrophoresis
- a dye to track the progression of the separation
- a dye to track the sample of interest
what 2 types of gel are used for gel electrophoresis and when are they generally used
Agarose gel for larger molecules
and polyacrylamide gel for smaller molecules
