Asked by Brooke Postlethwait on Sep 23, 2024
Verified
Which amino acid's side chain is positively charged at biological pH, pH = 7.4?
A) arginine
B) tyrosine
C) aspartic acid
D) serine
E) glutamine
Biological pH
The measure of acidity or alkalinity within living organisms or biological systems, crucial for maintaining homeostasis and enzymatic activities.
Positively Charged
Having a net positive electric charge due to the loss of electrons or an excess of protons.
Side Chain
The group of atoms attached to the main chain or backbone of a molecule, which can influence the molecule's properties and reactivity.
- Recognize the chemical characteristics of different amino acids.
Verified Answer
DW
DropIt with MahamAzhar Azhar4 days ago
Final Answer :
A
Explanation :
At physiological pH of 7.4, the side chain of arginine (R) is positively charged due to the presence of a guanidinium group. The other amino acids listed either have neutral (tyrosine, serine, glutamine) or negatively charged (aspartic acid) side chains at this pH.
Learning Objectives
- Recognize the chemical characteristics of different amino acids.