Question

Which of the pairs of amino acids can form a salt bridge at physiological pH? (multiple answers, select all that apply)

arginine and tyrosine

aspartic acid and histidine

two cysteines

lysine and glutamic acid

glutamic acid and aspartic acid

Answer 1

salt bridge is referred to the elctrostatic interactions between two oppositely charged molecules. So for the aa to form the slat bridge they have to either protonated or de protonated at physiological ph.

The correct combiantions in this case will be.- Lysine and glutamic acid as they are oppositely charged at ph 7

and Arginine and tyrosine. as the OH group of tyrosine will become O^- at the physiological ph.