Protein Engineering Practice Test 4

1. The wavelength of X – rays used in X – ray crystallography is 8 x 10^-10 m. It undergoes the first-order reflection at a glancing angle of 4.59°. What is the spacing between the atomic planes?

10 x 10^-9 m

4 x 10^-9 m

5 x 10^-9 m

15 x 10^-9 m

2. X – ray crystallography requires the formation of pure crystals to acquire accurate results.

True

False

3. Which of the following detector is used for proteins in the X – ray crystallography?

Scintillation counters

CCD cameras

Optical cameras

Proportional counters

4. Which of the following isotopes has a magnetic spin?

³¹P

¹⁶O

¹²C

¹⁴N

5. Which of the following lysosome is formed when primary lysosome fuses with cytoplasmic vacuole?

Autophagic vacuoles

Storage granules

Residual bodies

Heterophagosome

6. Which of the following rays can be utilized in cancer treatment to kill malignant cells?

Infrared rays

X – rays

Visible rays

Gamma rays

7. Macromolecular crystals are composed of approximately how much percent solvent on average?

95 percent

10 percent

50 percent

Zero percent

8. Which of the following is a correct feature for the free-interface diffusion method of protein crystallization?

The upper layer of a precipitant solution and lower layer of protein solution

The upper layer of protein solution and lower layer of precipitant solution

Only one layer of precipitant solution

Only one layer of protein solution

9. In the sitting drop vapour diffusion method the protein drop is suspended from a coverslip over the reservoir.

True

False

10. Crystallization of proteins proceeds in two distinct steps. Which are these steps?

Crystallization and expansion

Nucleation and growth

Solidification and crystallization

Growth and solidification