Lab practice Flashcards
In the Lambert-Beer law, the absorption is directly proportional to the thickness which is most times what value?
1cm and represents the length of the cuvete
The coefficient of extinction is L mol-1 cm-1(coefficient of molar extinction) if:
If the concentration is expressed in molarity (mol L-1)
The Law of Lambert-Beer is only valid for what kind of solutions?
Diluted solutions
in a solution with 1M concentration,
what is the value of the Absorvance?
Abs= coefficient of molar extinction
The blank cuvete used before measuring in the spectrophotometer is used to:
Discount the absorvance of the cuvete, solvent and any other component we will use to 0, so that only the absorvance of the substance we want to use will be measured
If the coefficient of correlation is less than 95%, it can mean that:
-The reaction is not reliable
-The linear relationship doesn’t exist
-the conditions of the experiment need to be optimized
To maintain the stable activity of the organelles in homogenization what is done:
Very low temperatures are used
The homogenization medium always contains :
A buffer solution
common Buffer solutions used are:
Tampao Fosfato e Tampao Tris-HCL
RPM e RCF indicates
Relative centrifugal force
Rotations per minute
parameters of centrifugation
RCF means:
N number of force times the gravitational force
before doing the centrifugation it is necessary to:
Make sure the opposite tubes are of the same weight
The material to be used in an electronic microscope has to be : a, b, c
Dehydrated, fixed and impregnated in a hard medium to be an ultra fine cut
what allows the ultra fine cut gotten from a biological material to achieve contrast of cellular structures when seen with a TEM?
Treated the material with heavy atoms (dense electrons)
