Question

The structure and general chemical composition of the cell membrane is similar to the membranes of organelles. True or false?

21. What is the proportion of H2N–CH2–COO–/+H3N–CH2–COO–at pH 9.6?

A) 100%/0%

B) 75%/25%

C) 50%/50%

D) 25%/75%

E) 0%/100%

44. Someone already filled in the information for a table comparing bacterial cells vs. eukaryotic cells regarding their surface- to-volume ratios (S/V). Assuming that both types of cells are spherical, the bacterium has a diameter of 1 μm, the animal cell has a diameter of 15 μm. The last column includes the internal membranes of the cell in the calculation of surface area, assuming internal membranes with 15 times the area of the plasma membrane. The volume of a sphere is given by V = 4pr3/3 and its surface by S = 4pr2, where r is its radius.

Calculate the value for the grayed table cell. Pay attention to all details on the table’s heading.

A) 640

B) 64.0

C) 6.4

D) 0.64

E) My result is different:

26. Briefly describe what is an ultracentrifuge. Compare and contrast an ultracentrifuge with a clinical centrifuge in terms of capabilities and applications.