Question

a student, not the instructor, in this class can grow their hair 36 inches in one year. Assuming that the increase in length is due only to growth of alpha-keratin, calculate the number of alpha-keratin helix turns synthesized by this student per minute. Recall that 1 inch= 2.54 cm. a) 1.34 X 10^3 turns/min b) 2.27 X 10^3 turns/min c) 3.22 X 10^3 turns/min d) 3.41 X 10^3 turns/min e) 9.42 X 10^14 turns/min

Answer 1

Ans. Growth rate of hair = 36 in / yr

= 36 x (2.54 cm) / yr                                     ; [1 in = 2.54 cm]

= 91.44 cm x 10⁸ A/ yr                                 ; [1 cm = 10⁸ A]

= (91.44 x 10⁸ A) / 525600 min                  ; [1 yr = 525600 min]

= 17397.26 A/ min

Now,

Number of a-helix repeats formed per min =

Hair growth rate/ length of helix per turn

= (17397 A/ min) / (5.4 A/ turn)

= 3.22 x 10³ trun/ min

Thus, correct option is- C