The lower the pka the stronger the acid o stronger

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The lower the pKa, the stronger the acid o Stronger tendency to give up its protons The higher the pKa, the stronger the base (smaller extent of dissociation) o Stronger tendency to accept protons Pepsin (i.e. the stomach enzyme) functions best at pH 2 since the carboxylic acid group on the amino acid in the active site of the enzyme must be in its protonated state. The carboxylic acid group is protonated at low pH, allowing it to catalyze the chemical reaction of breaking chemical bonds; the carboxylic acid group becomes deprotonated and cannot participate in chemical reactions at a pH higher than 2 Acidotic: an increased acidity in the blood and other body tissue (i.e. an increased hydrogen ion concentration); can occur if H+ ions build up in the blood Ionization of Glycine
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When an amino acid lacking an ionizable R group is dissolved in water at neutral pH, it exists in solution as a zwitterion o A simple monoamine monocarboxylic -amino acid (e.g. glycine), is a diprotic acid when fully protonated (i.e. it has two groups that can yield protons; the -COOH group and the -NH3+ group) Both the carboxyl and amino groups are protonated at low pH When the pH = pKa of the carboxyl group, 50% of the molecules in concentration have a deprotonated carboxyl group, 50% do not When the pH > pKa of the carboxyl group, glycine exists predominantly in its zwitterionic form (i.e. carboxyl is deprotonated) When the pH = pKa of the amino group, 50% of the molecules in concentration are in the zwitterionic form, and 50% are fully deprotonated At very high pH , glycine exists predominantly in its fully deprotonated form
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