6.4.1: Amino acids Flashcards
Amino acids two functional groups
COOH and NH2
carboxyl and amino groups
R group in amino acids
an organic side chain that is different in each amino acid
General amino acid structure
NH2-C-(H)(R)(COOH)
Amphoteric
has both acidic and basic properties
Why are amino acids amphoteric
the carboxyl group is acidic, can donate a H+
the amino group is basic, can accept a H+
Properties of amino acids
2
chiral molecules
amphoteric
Why are amino acids chiral molecules
the carbon usually has four different group attached
Two ways of naming amino acids
common and systemic name
When naming amino acids which group starts as carbon 1
the carboxyl group
Zwitterions
Dipolar ions that have both a positive and negative charge in different parts of the molecule.
Isoelectric point
The pH where the overall charge on the amino acid is zero.
Where do zwitterions exist
near an amino acid’s isoelectric point
What does the isoelectric point depend on
the R group of an amino acid
What are an amino acid’s functional groups like when its a zwitterion
NH2 is protonated to NH3+
COOH is deprotonated to COO-
In conditions more acidic than the isoelectric point what happens to the amino acid’s functional groups
and amino acid overall charge
COOH is unchanged
NH2 –> NH3+
amino acid has an overall positive charge
