Lab Techniques

Question 1

which type of chromatography uses a liquid stationary phase

Answer 1

gas liquid chromotography

Question 2

which type of chromotography involves separating molecules by size and molecular weight

Answer 2

size exclusion chromotography

Question 3

what type of chromotography involves separating molecules based on net charge

Answer 3

ion exchange chromotography

Question 4

what is affinity chromotography

Answer 4

selects molecules based on receptor ligand, enzyme-substrate and antigen-antibody interactions

Question 5

what is the point of gel electrophoresis

Answer 5

fragments of DNA and RNA of proteins are separated by size and charge

Question 6

true or false - larger particles can move quicker through the gel

Answer 6

false - only smaller particles can move quicker through the pores

Question 7

how does gel electrophoresis based on isoelectric points work

Answer 7

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

Question 8

what is the point of blotting

Answer 8

allows for easier manipulation and visualization of the molecules

Question 9

true or false - Western blotting is used to identify target fragments of a known `DNA sequence in a large population of DNA

Answer 9

false - this is called southern blotting

Question 10

true or false - southern blotting is used to identify a target protein in a mixture of proteins

Answer 10

false - this is western blotting

Question 11

what is the difference between a Southern and Northern blotting

Answer 11

Southern identifies DNA sequences but Northern identifies RNA sequences

Question 12

true or false - enantiomers have almost the exact physical and chemical properties

Answer 12

true

Question 13

what are the three ways to separate enantiomers

Answer 13

1. differences in crystallization
2. stereospecific enzymes can be added and only one enantiomer will react
3. enantiomers can be converted to diastereomers and visualized then

Question 14

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

Answer 14

NMR - arrangement of C and H atoms
functional groups
IR - functional groups
UV-Vis - presence of conjugated pi systems

Question 15

know the following chemical shifts

Answer 15

aldehyde protons = 9.5ppm
carboxylic protons = 10-12ppm
benzene protons = 8ppm
alcohol protons = 1-5ppm
methyl protons <1ppm

Question 16

know the following IR spectra regions

Answer 16

C=O - 1700 cm^-1
OH - 3200-3600 cm^-1
C=C - 2200cm^-1
CO - 1100cm^-1

Question 17

what is the precursor for Vitamin A

Answer 17

beta carotene

Question 18

what type of spectrometry is used to determine a compound’s molecular weight and formula

Answer 18

mass spectrometry

Question 19

true or false - nucleic acid manipulation is a type of genetic technique

Answer 19

true

Question 20

what is the point of nucleic acid manipulation

Answer 20

this technique is used to manipulate RNA and DNA so that they can be pulled apart or put together in different ways

Question 21

what is nucleic acid hybridization and what are the three double stranded combinations that can be made

Answer 21

it is a way to identify nucleotide sequences by binding a known sequence to an unknown one
RNA-RNA, DNA-RNA, DNA-DNA

Question 22

how do bacteria protect their own DNA from restriction enzymes

Answer 22

DNA methylation by adding a methyl group

Question 23

true or false - restriction sites are usually palindromic

Answer 23

true

Question 24

what are the two ways to clone DNA

Answer 24

through bacteria and a cDNA library or PCR

Question 25

what is the term used to identify a particular gene in a clone library and how does it work

Answer 25

hybridization - a complementary sequence of the target DNA is fluorescently labelled and used to search the library

Question 26

what are the 5 steps of PCR

Answer 26

loading, denaturing, annealing, replication and amplification

Question 27

what are the two methods to determine gene function?

Answer 27

1. observe gene evolution among different species

2. knock out - the target gene is deleted from the genome and then analyzed for its different properties

Question 28

how can gene expression be reduced

Answer 28

RNA interference

Question 29

what is RNA interference

Answer 29

small pieces of RNA bind to mRNA molecules, preventing translation