Living things are made from simple, common base
ingredients with four elements (C, O, H, N)
Conformation: Flexible. Can be changed without
breaking covalent bonds
Configuration: Fixed. Cannot be changed without
breaking covalent bonds
Geometric (cis-trans) isomers: have same chemical formula, but
differ in configuration of groups with respect to a non-rotating
double bond
o Cis: “on this side” groups on the same side of the double
bond
o Trans: “across” groups on opposite sides of the double bond.
Molecules can adopt different shapes in
different context to fulfill different
purposes.
o With respect to Double Bonds: cant
go from cis to trans and the other
way. (Have to break the double
bonds)
o With respect to Chiral Carbons:
Chiral Carbons: has four
different GROUPS (not
only immediate group after
the bond, but everything
after the bond to carbon is
considered a group)
These groups may be arranged in different ways yielding two stereoisomers
(same formula with different arrangement of atoms in space)
Chemical properties same; biological properties are different.
Chiral carbons have stereoisomers (L and D)
Construction and interaction are both stereospecific (Proteins are built entirely from L-Amino
acid)
Proteins
Linear polymers of amino acids (20 of them)
Protein folding: the characteristic of amino acids are going to determine how it’s going to fold
which in turn determine the biological activity (non polar in the middle and polar in the outside
people holding hands)
Linking of carboxyl group to amino group
ingredients with four elements (C, O, H, N)
Conformation: Flexible. Can be changed without
breaking covalent bonds
Configuration: Fixed. Cannot be changed without
breaking covalent bonds
Geometric (cis-trans) isomers: have same chemical formula, but
differ in configuration of groups with respect to a non-rotating
double bond
o Cis: “on this side” groups on the same side of the double
bond
o Trans: “across” groups on opposite sides of the double bond.
Molecules can adopt different shapes in
different context to fulfill different
purposes.
o With respect to Double Bonds: cant
go from cis to trans and the other
way. (Have to break the double
bonds)
o With respect to Chiral Carbons:
Chiral Carbons: has four
different GROUPS (not
only immediate group after
the bond, but everything
after the bond to carbon is
considered a group)
These groups may be arranged in different ways yielding two stereoisomers
(same formula with different arrangement of atoms in space)
Chemical properties same; biological properties are different.
Chiral carbons have stereoisomers (L and D)
Construction and interaction are both stereospecific (Proteins are built entirely from L-Amino
acid)
Proteins
Linear polymers of amino acids (20 of them)
Protein folding: the characteristic of amino acids are going to determine how it’s going to fold
which in turn determine the biological activity (non polar in the middle and polar in the outside
people holding hands)
Linking of carboxyl group to amino group
