1. Proteins

2. Proteins perform most functions in cells.

3. Characteristics of Proteins
Contain carbon, hydrogen, oxygen, nitrogen, and sulfur
Amino acids (monomers) are the basic building blocks of polypeptides (polymers) and polypeptides form proteins.
Functions:
structural components of cells
catalyzing chemical reactions (enzymes)
transporting substances within cells
messenger molecules (hormones)

4. Question Which of the following pairs of terms is INCORRECTLY matched?
fatty acid – steroid
monomer – polymer
amino acid – protein
monosaccharide – polysaccharide
Lipids such as fatty acids and steroids are the only group of biological macromolecules that do not consist of monomers joined together to form polymers.

5. Amino Acids
20 different types found in organisms – same basic structure.
Amino group acts like a base, tends to be positive.
Carboxyl group acts like an acid, tends to be negative.
“R” group is different for each amino acid (varying in size from 1-20 atoms).

6. Question 20
How many different types of amino acids are found in living things? (numeric response)

7. Some Amino Acids

8. Some More Amino Acids

9. Still More Amino Acids

10. Peptide Bonds
Adjacent carboxyl and amino groups covalently bond together, forming a peptide bond.
Two amino acids join together to form a dipeptide.
A chain of amino acids is called a polypeptide.

11. Question
What type of reaction is shown in this diagram illustrating the formation of a peptide bond?
Hydrolysis
Precipitation
Double replacement
Dehydration synthesis
Notice the removal of water required to form the bond.

12. Shape = Function
A functional protein consists of one or more polypeptides precisely twisted, folded, and coiled into a unique shape.
The shape of a protein determines its function.
Hemoglobin is an iron-containing protein in red blood cells that carries oxygen for delivery to cells. It consists of four polypeptides that fit together to form the final shape of the protein. Oxygen molecules bind to the iron portion (also called the heme group) of the hemoglobin molecule.

13. Denaturation
loss of normal shape of a protein due to heat or other factor

14. Levels of Protein Structure

15. Summary
Write of brief, comprehensive summary (3-4 sentences) of your notes, focusing on the main ideas and concepts.
Be prepared to share you summary with your classmates.