6. (a)Estimate the rms speed of an amino acid whose molecular mass is `89\ u` in a living cell at `37°C`. (b) What would be the rms speed of a protein of molecular mass `50,000\ u` at `37°C`?
6. (a)Estimate the rms speed of an amino acid whose molecular mass is 89\ u in a living cell at 37°C. (b) What would be the rms speed of a protein of molecular mass 50,000\ u at 37°C?
Hint
`v_(rms) = sqrt((2kT)/m)`
Answer
a) `v_(rms) = 2.9 times 10^2 m//s` b) `v_(rms) = 12 m//s`
Show Steps
Given: `T = 37°C = 310\ K` `m_a = 89\ u = 89 times 1.66 times 10^(-27)\ kg` `m_p = 50000\ u = 50000 times 1.66 times 10^(-27)\ kg` Known: `k = 1.38 times 10^(-23)\ J//K` Equation: `v_(rms) = sqrt((2kT)/m)` solution: a) `v_(rms) = sqrt((2kT)/m_a)` `v_(rms) = sqrt((2(1.38 times 10^(-23)\ J//K)(310\ K))/(89 times 1.66 times 10^(-27)\ kg))`
`v_(rms) = 2.9 times 10^2 m//s`
b) `v_(rms) = sqrt((2kT)/m_p)` `v_(rms) = sqrt((2(1.38 times 10^(-23)\ J//K)(310\ K))/(50000 times 1.66 times 10^(-27)\ kg))`
`v_(rms) = 12 m//s`