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Flashcards in Quiz 3 Deck (8)
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1

isoelectric point (pI) =

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

2

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

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

3

- @ 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

4

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

5

Histochemistry =

= the utilization of various stains and chemical staining procedures to visualize where specific cellular components are located in tissue sections (or thin layers of cells)

6

The basic steps in histotechnique: (4)

1.) The tissue or organ is removed from the organism and preserved = FIXATION

2.) The fixed tissue is sectioned (thinly sliced) using a microtome = SECTIONING

3.) The sectioned tissue is placed on a microscope slide and stained = STAINING

4.) The stained tissue sections are then permanently mounted = MOUNTING

7

Difference between native and non-native gel electrophoresis:

Native electrophoresis the proteins are held in their normal (Native) form
whereas with non–native electrophoresis the proteins are denatured (i.e., their normal 3-D structure is disturbed).

8

What role does the Nonidet P–40 serve in the extraction buffer?

Nonidet P-40 was used specifically for solubilising membrane proteins during an isolation of a membrane-protein complex. The role it served in this lab was to isolate the proteins from the membrane to solely receive a protein substance.