Lab Techniques Flashcards
which type of chromatography uses a liquid stationary phase
gas liquid chromotography
which type of chromotography involves separating molecules by size and molecular weight
size exclusion chromotography
what type of chromotography involves separating molecules based on net charge
ion exchange chromotography
what is affinity chromotography
selects molecules based on receptor ligand, enzyme-substrate and antigen-antibody interactions
what is the point of gel electrophoresis
fragments of DNA and RNA of proteins are separated by size and charge
true or false - larger particles can move quicker through the gel
false - only smaller particles can move quicker through the pores
how does gel electrophoresis based on isoelectric points work
a gel with a stable pH gradient is used. the proteins with a pH below the isoelectric point would be considered positively charged. these positive proteins would move towards the cathode. once all the proteins reach a point in the gel where that pH equals the isoelectric point, sharp bands will start to appear and the proteins will have no net charge
what is the point of blotting
allows for easier manipulation and visualization of the molecules
true or false - Western blotting is used to identify target fragments of a known `DNA sequence in a large population of DNA
false - this is called southern blotting
true or false - southern blotting is used to identify a target protein in a mixture of proteins
false - this is western blotting
what is the difference between a Southern and Northern blotting
Southern identifies DNA sequences but Northern identifies RNA sequences
true or false - enantiomers have almost the exact physical and chemical properties
true
what are the three ways to separate enantiomers
- differences in crystallization
- stereospecific enzymes can be added and only one enantiomer will react
- enantiomers can be converted to diastereomers and visualized then
match the following structural information to the type of spectroscopy used to find it
NMR
IR
UV-Vis
arrangement of C and H atoms
functional groups
presence of conjugated pi systems
NMR - arrangement of C and H atoms
functional groups
IR - functional groups
UV-Vis - presence of conjugated pi systems
know the following chemical shifts
aldehyde protons = 9.5ppm carboxylic protons = 10-12ppm benzene protons = 8ppm alcohol protons = 1-5ppm methyl protons <1ppm
know the following IR spectra regions
C=O - 1700 cm^-1
OH - 3200-3600 cm^-1
C=C - 2200cm^-1
CO - 1100cm^-1
what is the precursor for Vitamin A
beta carotene
what type of spectrometry is used to determine a compound’s molecular weight and formula
mass spectrometry
true or false - nucleic acid manipulation is a type of genetic technique
true
what is the point of nucleic acid manipulation
this technique is used to manipulate RNA and DNA so that they can be pulled apart or put together in different ways
what is nucleic acid hybridization and what are the three double stranded combinations that can be made
it is a way to identify nucleotide sequences by binding a known sequence to an unknown one
RNA-RNA, DNA-RNA, DNA-DNA
how do bacteria protect their own DNA from restriction enzymes
DNA methylation by adding a methyl group
true or false - restriction sites are usually palindromic
true
what are the two ways to clone DNA
through bacteria and a cDNA library or PCR
what is the term used to identify a particular gene in a clone library and how does it work
hybridization - a complementary sequence of the target DNA is fluorescently labelled and used to search the library
what are the 5 steps of PCR
loading, denaturing, annealing, replication and amplification
what are the two methods to determine gene function?
- observe gene evolution among different species
2. knock out - the target gene is deleted from the genome and then analyzed for its different properties
how can gene expression be reduced
RNA interference
what is RNA interference
small pieces of RNA bind to mRNA molecules, preventing translation
