1-15-10ProteinStructureEnzymesJunctions - BIOL13100 Biology...

BIOL13100
Biology II: Development, Structure, and
Function of Organisms
January 15, 2010
Dr. Nancy Pelaez
Lilly G-224
[email protected]

Table 3-1

Amino Acids
R
C C
O
OH
H
2
N
H
The alpha
carbon

Amino Acid in Water at pH 7
R
C C
O
O
H
2
N
H
The alpha
carbon
3

Figure 3-2
Non-ionized form of amino acid
Ionized form of amino acid
Amino
group
Amino
group
Carboxyl
group
Carboxyl
group
Side chain
Side chain
Non-ionized
Non-ionized
Ionized
Ionized

Figure 3-3
Nonpolar
side chains
Polar side
chains
Electrically
charged
side chains
Glycine (G)
Gly
Alanine (A)
Ala
Valine (V)
Val
Leucine (L)
Leu
Isoleucine (I)
Ile
Methionine (M)
Met
Phenylalanine (F)
Phe
Tryptophan (W)
Trp
Proline (P)
Pro
Serine (S)
Ser
Threonine (T)
Thr
Cysteine (C)
Cys
Tyrosine (Y)
Tyr
Asparagine (N)
Asn
Glutamine (Q)
Gln
Acidic Basic
Aspartate (D)
Asp
Glutamate (E)
Glu
Lysine (K)
Lys
Arginine (R)
Arg
Histidine (H)
His
No charged or
electronegative
atoms to form
hydrogen
bonds; not
soluble in water
Charged side
chains form
hydrogen
bonds; highly
soluble in
water
Partial charges
can form
hydrogen
bonds; soluble in
water

Figure 3-5
Polymer
Polymerization
(bonding together of monomers)

Peptide Bond Formation Between
Two Amino Acids
R
C C
O
OH
H
2
O
H
2
N
H
1
R
C C
O
OH
H
2
N
H
2
+
R
C
H
2
N
H
1
R
C C
O
OH
H
2
+

A Tri-peptide in water at pH 7
Alanine
Aspartic acid
Valine

Proteins are polymers of amino acids.
A protein has an N-terminus and a C-
terminus.
N-Glu-Ala-Ile-Thr-…..Gly-Ala-Ala-Ala-Thr-Ser-C
The primary structure of a protein is the
sequence of the amino acids.

Figure 3-6
(Water)
(Water)
Condensation reaction: monomer in, water out
Hydrolysis: water in, monomer out

Figure 3-7
Carboxyl
group
Amino
group
Peptide
bond
Electrons shared between
carbonyl group and peptide
bond offer some characteristics
of double bonds