Determining molecules of actin per cell and number of mitochondria?

[bebe1018_87]

hello, if anyone could help me with these biochem problems I will greatly appreciate it!

 

a) if you magnify a cell 10,000 fold, how big will it appear if the the is eukaryotic with a cellular diameter of 50micrometers?

 

I did 50micrometer= 5.0x10^-5m

5.0x10^-5m times 10,000= 0.5m

0.5m equals 500mm, which is the answer, but how do I solve the following parts?

 

b) if the cell was a muscle cell, how many actin molecules could it hold, if the cell is spherical and there are no other cellular components present and actin molecules are spherical with a 3.6nm diameter. and the volume of the sphere is 4/3(pi)®^3.

 

I did 3.6nm/2= radius= 1.8nm=1.8x10^-9m

the 50micrometers of the cell equal 5.0x10^-5m

 

then I did 5.0x10^-5m/1.8x10^-9m= 2.77777777x10^8, but the answer is 2.7x10^12 actin molecules

 

c) if this were a liver cell of the same dimensions how many mitochondria could it hold? (the cell is also spherical, no other components present and the mitochondria are spherical with a diameter of 1.5micrometers)

The answer is 36,000 mitochodria, but how do I solve it?

[Des-Rez]

You divided the diameter of the cell by the dimension of the actin.

 

B)

(5x10^-5m)/2 = 2.5x10^-5m

(4/3)(pi)(2.5x10^-5m)3 = 6.5450x10^-14m ----> cell dimension

 

3.6x10^-9m/2 = 1.8x10^-9m

(4/3)(pi)(1.8x10^-9m)3 = 2.4429x10^-26m ----> actin dimension

 

6.5450x10^-14m / 2.4429x10^-26m = 2.6792x10^12 ----> 2.7x10^12 actin

 

C)

1.5x10^-6m/2 = 7.5x10^-7m

(4/3)(pi)(7.5x10^-7m)3 = 1.7671x10^-18m ----> mitochondion dimesion

 

6.5450x10^-14m / 1.7671x10^-18m = 37038.085 mitochondria ----> I apologize if this is not accurate enough