Epinephrine contains an acidic amine hydrogen described by the following equilibrium:R2NH + H+ ↔ R2NH2+ (pKa = 8.55).When epinephrine is released into the bloodstream during a “fight or flight” response, most epinephrine molecules will: (Note: pH of blood = 7.4)A.be uncharged.B.carry a 1- charge.C.carry a 1+ charge.D.be zwitterionic
Question
Epinephrine contains an acidic amine hydrogen described by the following equilibrium:R2NH + H+ ↔ R2NH2+ (pKa = 8.55).When epinephrine is released into the bloodstream during a “fight or flight” response, most epinephrine molecules will: (Note: pH of blood = 7.4)A.be uncharged.B.carry a 1- charge.C.carry a 1+ charge.D.be zwitterionic
Solution
The pKa of a substance is the pH at which half of the substance is in its protonated form and half is in its deprotonated form. If the pH is less than the pKa, the substance will be mostly protonated. If the pH is greater than the pKa, the substance will be mostly deprotonated.
In this case, the pKa of the amine group in epinephrine is 8.55. The pH of blood is 7.4, which is less than the pKa. Therefore, in the bloodstream, the amine group in epinephrine will be mostly protonated, meaning it will carry a 1+ charge.
So, the correct answer is C. Most epinephrine molecules will carry a 1+ charge when released into the bloodstream during a “fight or flight” response.
Similar Questions
is Epinephrine local regulators ?
Fill in the Blank QuestionFill in the blank question.Epinephrine and norepinephrine are synthesized in the portion of the adrenal gland called the adrenal .
When the kidney secretes hydrogen ions, it lowers the pH of the urine.Group of answer choicesTrueFalse
The patient received a dose of epinephrine. What did this do to their heart rate?Multiple Choiceincreases itdecreases itstops itdoes not alter itmakes it skip every other beat
L'adrénaline:AEst synthétisé à partir de la noradrénaline grâce au phenylalanine hydroxylaseBPossède une demi vie de 4 minCAgit exclusivement sur les récepteurs aDAgit exclusivement sur les récepteurs ALPHA .EAgit sur les récepteurs ALPHA et BETA .
Upgrade your grade with Knowee
Get personalized homework help. Review tough concepts in more detail, or go deeper into your topic by exploring other relevant questions.