# physics

The membrane that surrounds a certain type of living cell has a surface area of 4.50 × 10-9 m2 and a thickness of 1.00 × 10-8 m. Assume that the membrane behaves like a parallel plate capacitor and has a dielectric constant of 5.3. The potential on the outer surface of the membrane is +62.0 mV greater than that on the inside surface. If the charge is due to positive ions (charge +e), how many such ions are present on the outer surface?

1. 0
2. 0
3. 9
1. q = kappa epsilon A V/d
q = 5.3* 8.8e-12 * 4.5e-9 *62e-3 / 1e-8

Once you have this number the charge of a single ion (1.67e-19) to find out how many charges you need.

1. 0
2. 0
posted by Chanz

## Similar Questions

1. ### Physics

The membrane that surrounds a certain type of living cell has a surface area of 2.13 x 10-9 m2 and a thickness of 1.94 x 10-8 m. Assume that the membrane behaves like a parallel plate capacitor and has a dielectric constant of

asked by Sami on February 10, 2012
2. ### physics

The membrane that surrounds a certain type of living cell has a surface area of 4.9 x 10-9 m2 and a thickness of 1.2 x 10-8 m. Assume that the membrane behaves like a parallel plate capacitor and has a dielectric constant of 5.5.

asked by Shannon on February 18, 2013
3. ### physics

The membrane that surrounds a certain type of living cell has a surface area of 4.4 x 10-9 m2 and a thickness of 1.6 x 10-8 m. Assume that the membrane behaves like a parallel plate capacitor and has a dielectric constant of 4.1.

asked by help on January 19, 2013
4. ### Physics

The membrane that surrounds a certain type of living cell has a surface area of 4.50 10-9 m2 and a thickness of 1.08 10-8 m. Assume that the membrane behaves like a parallel plate capacitor and has a dielectric constant of 5.40.

asked by Julie on February 26, 2013
5. ### Biology

All cell are surrounded by membranes. The main role of the cell membrane is to A.regulate the cell's interactions with the environment b.release any type of molecule out of the cell c.arrange the cell's organelles in the cytoplasm

asked by Mario Garcia on October 17, 2011
6. ### Biology

All cell are surrounded by membranes. The main role of the cell membrane is to A.regulate the cell's interactions with the environment b.release any type of molecule out of the cell c.arrange the cell's organelles in the cytoplasm

asked by Mario Garcia on October 17, 2011
7. ### physics 2

The inner and outer surface of a cell membrane carry a negative and a positive charge, respectively. Because of these charges, a potential difference of about 0.070 V exists across the membrane. The thickness of the cell membrane

asked by Diane on February 4, 2010
8. ### physics

An axon is the relatively long tail-like part of a neuron, or nerve cell. The outer surface of the axon membrane is charged positively, and the inner surface is charged negatively. The membrane itself has a dielectric constant k ~

asked by edd on February 11, 2010
9. ### Biology

Which of the following statements best explains how the cell membrane regulates what goes in and out of the cell? A. the membrane allows only certain molecules to move into the cell B. the membrane destroys most molecules so that

asked by Behind In School on September 19, 2018
10. ### biology

Why is a large surface area : volume ratio needed for cells to function properly? a.Adequate surface area (plasma membrane) is needed to furnish nutrients to and expel wastes from the volume (cytoplasm). b. Smaller volumes reduce

asked by CHARLOTTE on October 1, 2009

More Similar Questions