Spontaneous depurination of DNA occurs at the rate of approx

Spontaneous depurination of DNA occurs at the rate of approximately 3 x 10^-9 depurination per purine nucleotide per minute. A diploid human cell has approximately 6 x 10^9 base pairs of DNA. Approximately how many spontaneous depurinations must be repaired per day in each diploid cell?

Solution

Each of the base pairs have one purine that undergoes spontaneous dupurination at the rate of approximately 3x10^-9 depurinations per purine nucleotide per minute.

Diploid human cell contains 6x10^9 base pairs which means there should occur: 3x10^-9 * 6x10^9 =18 depurinations per minute.
Per day means 24 hours i.e 60 * 24 minutes

In one minute number of depurinations = 18

So, in a day,the number of depurinations in each diploid cell will be :18* 60*24 = 25920 (ans)