Transcript 14. Protein Structure notes

PROTEINS
June 2, 2016
Functions
1.
2.
Building Blocks
a. Structural components of many cells
Antibodies
a. Involved in defending the body against
foreign invaders
Functions (cont.)
3.
Enzymes
a. Catalyze chemical reactions
b. Examples: Amylase and Lactase
c. They can become Denatured
1. When they lose their function and shape
in extreme conditions
2. Examples: milk souring, cooking eggs
Functions
4.
5.
Signaling
a. Cells signal one another
1. Example: Muscle contraction
Transporters
a. Bind to molecules and carry them to other
cells
Macromolecule Units Review


Monomer
 Smallest unit of macromolecule
Polymer
 Formed when many monomers bond
How do you make Macromolecules?

Dehydration Synthesis
 Polymers
are formed by removing water from
monomers
How do you break a macromolecule?

Hydrolysis
 Polymers
are broken apart by adding water to break
up into individual monomers
Structure
1.
Made up of monomer units called…
 Amino Acids
a. Bonded together through the process of…..

b.
Dehydration Synthesis
Break polymers up through process of…
 Hydrolysis
A
D
B
C
Functional Groups Commonly Present
1.
Amino Group
2.
Carboxyl Group
Amino Acid Structure
1.
Each Amino Acid has a different combination
of elements labeled simply as its “R Group”
a. 20 total
Amino Acids
Nonpolar
Basic
Polar
Acidic
4 Levels of Structure
1.
Primary Structure
a. A chain of amino acids
1. Bonds between amino acids
are covalent or peptide bonds
*NOW IT’S CALLED A POLYPEPTIDE (long chain
of amino acids)
*Each polypeptide differs in
the number & arrangement
of the amino acids’ R groups
Formation of a peptide bond
Formation of a peptide bond (cont.)
Protein Structure
4 Levels of Structure (cont.)
2.
Secondary Structure
a. Arrangement of polypeptides into different
formations
1. Alpha helix: Coil or corkscrew formation
2. Beta Sheet: Pleats or folds
3. Random Coils
Hydrogen bonding present
between an H and O
b.
Hydrogen Bonding: Alpha and Beta
4 Levels of Structure (cont.)
3.
Tertiary Structure
a. 3-D folding of secondary structures
b. Bonding occurring within the protein due to interaction of
R groups
Types of R group bonds
1. Hydrophobic interactions occur between Nonpolar R
groups
2. Ionic Bonds- occur b/w an acid (-) & base (+)
3. Disulfide bonds- occur b/w 2 cysteine R groups
4. Hydrogen bonds- occur b/w Polar R groups in which
an N, O, or F will be present (some exceptions)
a. At this stage it is a functional protein
Bonding in Tertiary Structure
4 Levels of Structure (cont.)
1.
Quaternary Structure
a.
Tertiary proteins bond with each other (2 or more
polypeptides bond), so you have a group of proteins
bonded together
b.
Example: Hemoglobin