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Amino Acids
General Properties
The four most abundant elements in living organisms - CHON
The six most essential elements of life - CHNOPS
Tetrahedral carbon
tetravalent - four electrons available to form covalent bonds
tetrahedral geometry - central carbon with four single bonds pointing away from
each other at the same angle = 109,5 degrees
Double and Triple bonds
Double bonds:
Atoms participating at double bond
cannot freely rotate.
Double/Triple bond is planar
In cases where carbon atoms
engage in two double bonds or a
triple bonds plus a single bond is
linear
Catenation - the ability of a
chemical element (carbon
structures) to form long chain-like
structures via a series of covalent
bonds
Amino Acids 1
, Chirality
alpha-carbon is
chiral/assymetrical/stereocenter
when four different chemical groups
is attached to it.
Enantiomers - superimposable
mirror images of each other
Skeletal formula - only carbon
atoms and functional groups (no
hydrogens)
In the absense of an ionizable side chain (R-group) amino acids exist at neutral
pH as a zwitterion/dipolar ion, which can act as either an acid (H donor) or base
(H acceptor).
At neural pH - protonated positively charged amino group and deprotonated
negatively charged carboxyl group.
Amphoteric/Ampholytes - molecules with dual base/acid properties
Low pH → protonated amino group; net charge = +1
High pH → deprotonated carboxylic acid; net charge = -1
Peptide bond is formed when alpha-carboxyl and alpha-amino groups of two
amino acids react in a condensation reaction, releasing one molecule of H20 =
dipeptide
Classification
Amino Acids 2
Amino Acids
General Properties
The four most abundant elements in living organisms - CHON
The six most essential elements of life - CHNOPS
Tetrahedral carbon
tetravalent - four electrons available to form covalent bonds
tetrahedral geometry - central carbon with four single bonds pointing away from
each other at the same angle = 109,5 degrees
Double and Triple bonds
Double bonds:
Atoms participating at double bond
cannot freely rotate.
Double/Triple bond is planar
In cases where carbon atoms
engage in two double bonds or a
triple bonds plus a single bond is
linear
Catenation - the ability of a
chemical element (carbon
structures) to form long chain-like
structures via a series of covalent
bonds
Amino Acids 1
, Chirality
alpha-carbon is
chiral/assymetrical/stereocenter
when four different chemical groups
is attached to it.
Enantiomers - superimposable
mirror images of each other
Skeletal formula - only carbon
atoms and functional groups (no
hydrogens)
In the absense of an ionizable side chain (R-group) amino acids exist at neutral
pH as a zwitterion/dipolar ion, which can act as either an acid (H donor) or base
(H acceptor).
At neural pH - protonated positively charged amino group and deprotonated
negatively charged carboxyl group.
Amphoteric/Ampholytes - molecules with dual base/acid properties
Low pH → protonated amino group; net charge = +1
High pH → deprotonated carboxylic acid; net charge = -1
Peptide bond is formed when alpha-carboxyl and alpha-amino groups of two
amino acids react in a condensation reaction, releasing one molecule of H20 =
dipeptide
Classification
Amino Acids 2
