Test one Flashcards
whats the capacity for p-10
.5 microliters to 10 microliters
whats the accuracy for p-10
.2 microliters
whats the capacity for p-20
2 to 20 microliters
whats the accuracy for p-20
.2 microliters
whats the capacity for p-200
20 microliters to 200 microliters
whats the accuracy for p-200
2 microliters
whats the capacity for p-1000
200 microliters to 1000 microliters
whats the accuracy for p-1000
20 microliters
how to find percent error
(measured-avg)x 100
what are the units for molarity
mol/L
what are the units for molecular weight
g/mol
molecular weight can also be expressed in
daltons
when two components at the same concentration are mixed whats the dilution
no dilution
what is spectrophotometry
measurement of how much a chemical substance absorbs or transmits
what is a wavelength
distance between two consecutive crests or troughs
what is amplitude
height of wave crest above the reference line, shows intensity of wave
what is frequency
number of oscillations per second
shorter wavelength has what type of energy
high
longer wavelength has what type of energy
low
visible light wavelength range
340 to 800
UV wavelength range
200 to 340
when the electron falls back into the ground state, the excess energy is lost as
heat or fluorescence
white light is composed of
all colors
if an object absorbs all wavelengths of visible light, it appears…
black
if the absorption spectra is showing for a certain color, what happens
the complimentary color is shown
absorbance is proportional to what
length of sample holder and concentration
units for extinction coefficient
M-1, cm-1
purpose of bradford assay
measure protein concentration
units of dalton are
g/mol
you can estimate molar extinction coefficient usin
amino acid composition
how is cystine formed
when two cysteine residues form a disulfide bond
if cystine is in cytosol what happens
does not occur
what are the four chromogenic assay methods for determining protein concentration
biuret method, lowry assay, BCA method, Bradford assay
what are the two wavelengths that proteins absorb
220, 280
absorbance for a protein depends on what three things
tryptophan, tyrosine and cystine
Biuret method
uses copper, no worries about free aa, no aromatic aa, not very sensitive
lowry assay
2 step, uses copper, very sensitive, many compounds can interfere
BCA method
uses copper, one step, many compounds can interefere
bradford assay
uses blue dye, sensitive, not dependent on aromatic aa
wavelength of nucleic acid absorbtion
260 nm
what interrupts resonance and limits absorbance in DNA
h bonds
denaturing of RNA/DNA causes increased what
absorbance
