1. Proteins

2. Protein Basics Made of C,H,O, N SPONCH Monomers = amino acids
- 20 different types of amino acids used to make proteins
Proteins are the polymer also called a polypeptide

3. Meet the monomer –Amino acid
3 main parts
- Amino group NH2
- Carboxyl group COOH
- R group (side chain)
each of the 20 types
of amino acids have
a unique R group

5. Proteins form from chains of amino acids
Proteins vary in length – can be 1,000s of amino acids long
Protein

6. Proteins Shape
A protein’s shape is determined by the order that amino acids are joined in
The shape of a protein determines its function
Hemoglobin antibody enzymes polymerase

7. Protein Structure
Four Levels of Structure allow for any shape
2-28

8. Protein Structure – Primary Structure
Primary structure is the order of the amino acids that make up a protein.
- the interactions of the R groups on each amino acid
cause the molecule to bend and fold – different arrangements create different shapes
- as a result- the order of
amino acids determines
the shape of the protein
- shape determines function
- changing a single amino acid can change a protein’s
shape.

9. Protein Structure- Secondary Structure
The folding proteins often assume one of two general shapes
– pleated sheets or an alpha helix these are the protein’s secondary structure.
- hydrogen bonds between amino acids stabilize the secondary structure
Alpha Helix

10. Protein Structure – Tertiary Structure
The coiled or pleated structures continue to fold until
they form a complex three dimensional structure.
- most proteins are completed at this stage and are fully functioning proteins.
Remember: Shape determines function

11. Protein Shape-Quaternary Structure
Some more complex proteins are assembled from two
or more protein molecules.
- Insulin – 2 forms – 2 proteins or 6 proteins
- Hemoglobin – 4 proteins

12. Protein Functions Proteins are the Worker Molecules of Living Things
Enzymes - proteins that allow chemical reactions to
occur in living things
Antibodies – proteins that protect the body from infection
Structure – cytoskeleton, hair, nails, muscles, spider web, silk, feathers ,horns, hooves etc….
Hormones – chemical messengers
Cell membrane – proteins can act as channels through the cell membrane
- receptor proteins found on membrane
transmit signals to the inside of cells
Hemoglobin – protein found in blood that carries oxygen

14. Proteins can be Denatured
Denatured proteins are proteins that lose their shape
- if they lose their shape, they also lose their
- What can cause a protein to become denatured?
Exposure to: A Strong Acid
A Strong Base
Heat
An organic solvent: Alcohol or Acetone
- Denatured proteins can lose quaternary, tertiary and
secondary structure
- Primary Structure is left untouched …
Function

15. Denatured Proteins

16. Vocabulary for the Protein Pro
Polypeptide
R – Group
Peptide Bond
Primary Structure
Secondary Structure
Tertiary Structure
Quaternary Structure
Enzymes
Antibodies
Cell Membrane Proteins
Hormones
Denatured Protein
4 things that denature proteins