MYTUTOR SUBJECT ANSWERS

497 views

How do amino acids change at different pH?

Amino acids are amphoteric which means they can act as an acid or a base.

An isoelectric point is the pH at which an amino acid exists as its zwitterion. A zwitterion is the dipolar ionic form of an amino acid. This is formed by a hydrogen ion (H+) from the carboxyl group being donated to the amino group. There is no overall charge. The carboxyl group becomes COO- and the amino group becomes NH3+ showing an imbalance of charge that makes it a polar molecule.

If the pH is lower (in acidic conditions) than the isoelectric point then the amino acid acts as a base and accepts a proton at the amino group. This gives it a positive change.

If the pH is higher (in alkaline conditions) than the isoelectric point then the amino acid acts as an acid and donates a proton from its carboxyl group. This gives it a negative charge.

Zoe C. A Level Biology tutor, GCSE Biology tutor, A Level Geography t...

9 months ago

Answered by Zoe, an A Level Chemistry tutor with MyTutor


Still stuck? Get one-to-one help from a personally interviewed subject specialist

116 SUBJECT SPECIALISTS

£24 /hr

Eleanor H.

Degree: Biochemistry (Bachelors) - Bristol University

Subjects offered:Chemistry, Maths+ 1 more

Chemistry
Maths
Biology

“ABOUT ME: I am a biochemistry student, currently studying at the University of Bristol, and have had a passion for the natural sciences from a very young age. I am patient, hardworking and experienced, having tutored students in Maths...”

£22 /hr

George N.

Degree: Chemistry (Masters) - York University

Subjects offered:Chemistry, Physics

Chemistry
Physics

“20 year old second year chemistry student at the University of York. Drummer, guitarist, rugby player and radio host who has experience and a love for tutoring.”

PremiumLorenzo C. GCSE Biology tutor, A Level Biology tutor, GCSE Chemistry ...
£26 /hr

Lorenzo C.

Degree: Biomedical Sciences with Honours in Infectious Diseases (Bachelors) - Edinburgh University

Subjects offered:Chemistry, Physics+ 1 more

Chemistry
Physics
Biology

“5th in the World at International A-Level Biology Over two years experience in tutoring!”

About the author

Zoe C.

Currently unavailable: for new students

Degree: Biological Sciences (Bachelors) - Exeter University

Subjects offered:Chemistry, Geography+ 1 more

Chemistry
Geography
Biology

“My name is Zoe and I am currently studying biological sciences at the University of Exeter. I absolutley love science and I would love to tutor you so you can discover the wonders of science too. At A level I studied biology, chemistr...”

You may also like...

Posts by Zoe

How are amino acids involved in condensation and hydrolysis reactions?

How do amino acids change at different pH?

What are amino acids?

What is chirality? Why is it seen in amino acids?

Other A Level Chemistry questions

Why does ethanoyl chloride have a lower boiling point that pentanoyl chloride?

Which has a lower boiling point chlorine or bromine, and why?

What is the trend in atomic radius of the elements across Period 3 and why does this occur?

What are Van Der Waals dispersion forces?

View A Level Chemistry tutors

We use cookies to improve your site experience. By continuing to use this website, we'll assume that you're OK with this. Dismiss

mtw:mercury1:status:ok