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Flashcards in Lab Final Deck (60)
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Logarithmic Graphs are used to...

the dependent variable plots as...

...when it is proportional to...

- represent large numbers in a short space

- a straight line

- a constant power of the
independent variable.


Semi-logarithmic Graphs are used when...

successive values of one quantity increase in geometric
progression as another quantity increases in arithmetic progression.


Linear Scale Graphs are used when...

relationships are in non-geometric progression.


The independent variable belongs on the

The dependent variable belongs on the

x-axis (horizontal line)

y-axis (vertical line)


What is bolded in a figure/graph

Table 1/Figure1


Where does the title go:
on a graph =
on a table =

graph = title below
table = title below


What is the difference between a logarithmic and semi-logarithmic graph?

Log graphs have x & y axis as log functions (also used when we have large values in a small scale)
Semi-log graphs have either x or y as log functions (also used when one value is progressing geometrically but the other is progressing arithmetically)


True or False:
Dependent variables are plotted on the abscissa

False, the independent variable is plotted on the abscissa


x axis =
y axis =

x = abscissa = independent
y = ordinate = dependent


practice quiz 1 question 3

plzzzz don't u want a big fat throbbing AAAAA


practice quiz 1 question 4

plzzzz don't u want a big fat wet AAAAA


What is calibration? Explain calibration relative to photospectrometry:

Calibration is comparing what you have to what is known in order to set a standard/control in an experiment without calibration in photospectrometry values would be inaccurate


True or False:
Working distance (distance between the objective and the slide where the slide is in focus) of the microscope increases as the magnification power of the objective lens increases



The revolving power improves by changing the yellow light source to (red or violet)



resolving power equation

d = lambda / (NAoc - NAobj)


Higher wavelength means _____ resolving power



the resolution can improve with the increase or decrease in numerical aperture




light of one wavelength/nm (incident beam Io)


True or False:
A standard curve can be established by measuring the absorbance of a solution at various concentrations



- Cell fractionation is...
- by either...

- ...a general procedure that consists of disrupting the cell membrane (and cell wall of plants) to release the cell contents and then separate the organelles based upon differences in size or density
- ...differential centrifugation or density gradient centrifugation.


isoelectric point (pI) =

the pH at which a particular molecule carries no net electrical charge or is electrically neutral


At a pH below their pI, proteins carry...
At a pH above their pI, proteins carry...

...a net positive charge
...a net negative charge.


- @ its pI, proteins are at their...
- Therefore, by changing the pH of the solution to the pI, the...

...lowest solubility (due to net 0 charge)
...solubility of the protein will be lowered


- As the salt concentration is increased...
- Further increases in the salt concentration result in...
- Finally, the protein starts to...
- This phenomenon of protein precipitation in the presence of excess salt is known as...

... a point of maximum protein solubility is usually reached
...fewer water molecules available to solubilize protein (since the water molecules are being used to solubilize the salts)
...precipitate when there is not a sufficient number of water molecules to interact with (solubilize) the protein molecules


- At low salt concentrations...
- This is commonly known as...

...the presence of salt stabilizes the various charged groups on a protein molecule, thus attracting the protein into the solution and enhancing the solubility of protein.


the role of temperature in fractionation of cellular components such as chloroplasts, mitochondria and proteins =

cold to stop enzyme reactions/maintain the integrity of the organelles and enzymes during the fractionation procedure


some factors that can effect protein function:

pH, temperature, fixation, etc


Lowry Assay Methods:

1.) Prepare a series of BSA protein standards from 0.8 to 0.025 mg/ml
2.) Prepare your unknowns (from lab 7) according to instructor specifications. (Try diluting S1b and S2 to 1/10 concentration by separately adding 100 μl of the each protein solution to 900 μl of HB. Dilute the resuspended microfibil pellet to 1/10 concentration by adding 100 μl of HB to 900 μl of FRB. Save the remainder of each protein extraction for a future lab).
3.) Prepare 15 ml tubes by labeling them as either BSA concentration, blank or unknown (10 tubes total). Add 1.5 ml of Solution A to each tube then 1.0 ml of either BSA, diluted unknown, or deionized water to the appropriately labeled tube.
4.) Let the solutions sit for 15 minutes at room temperature.
5.) During this time dilute 5 ml of Solution B with 5 ml of H20. It is now at 1.0 N. (There will be an aliquot of diluted Solution B under the fume hood. Only do this step if there is not enough dilute Solution B in the aliquot).
6.) Add 0.4 ml of Solution B to each tube.
7.) Let the solutions sit for 15 min at room temperature. (Precipitate may form at the bottom of the tubes. If so do not resuspend the precipitate or pipette it into the curvette in the next step.)
8.) Read all of the absorbances in the Spec 20 at a wavelength of 580 nm (Curvettes are full at 2.5 ml solution. Do not overfill them. Be sure to calibrate using the blank between measurements.)
9.) Plot a standard curve.
10.) Calculate the protein concentrations for each of the unknowns


Bradford Assay is based on...

When the dye binds to the protein...

The amount of light absorbance at a wavelength of 595 nm is directly proportional to...

- the simple binding affinity for a particular dye (Bio Rad Protein Assay Dye) to protein.

- it changes from red to blue.

- the amount of protein


Beer's Law

The amount of light absorbance at a wavelength of 595 nm is directly proportional to the amount of protein