What fraction of alanine is in the completely uncharged form at its pI

来源：百度知道 编辑：UC知道 时间：2024/05/24 14:44:26
pka 2.34 9.69 pI:6.01

解答说用henderson-hasselbalch 公式, 就得出了1/4680 carboxyl groups and 1/4680 amino groups are uncharged

然后答案就是2个乘一下 2.19*10^7

[Henderson-Hasselbalch equation;
ph=pka+log10([A-/[HA)]

for carboxyl group, pka=2.34
then

at pI=6.01
6.01=2.34+log10(coo-/cooH)
hence

coo-/cooH=4680

uncharged/charged=1/4680

for amino groups
pka=9.69

then at pi=6.01
6.01=9.69+log10(NH3/NH4+)
then NH3/NH4+=1/4680, thus uncharged/charged=1/4680

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