1. Proteins… Let’s Review…… then….. Let’s discover proteins….
PollEv.com/tinalambiase209

2. Functions of Proteins …
Enzymes – reduces activation energy
Ex: amylase – helps to digest amylose
ATP synthase – helps to make ATP
Structural Proteins – provide support
ex: elastin, horn, silk (web), keratin (hair & nails)
Movement – actin and myosin muscles
Defense – antibodies in bloodstream
Storage – albumin in egg whites
Signaling – growth hormones in bloodstream

3. FIGURE 3-17a Structural proteins
Common structural proteins include keratin, which is the predominant protein found in (a) hair, (b) horn, and (c) the silk of a spider web.

4. FIGURE 3-17b Structural proteins
Common structural proteins include keratin, which is the predominant protein found in (a) hair, (b) horn, and (c) the silk of a spider web.

5. What do you think is happening to the proteins within these eggs????

6. Proteins C, H, O, N and sometimes S Made in ribosomes Cell membranes
Hormones (insulin)
Hemoglobin
Enzymes (control the rate of reactions)

7. Proteins Proteins are made of Amino Acids
There are 20 different amino acids. Each having a similar general structure - Differ only in their “R” groups

8. Peptide Bonds
Amino acids form proteins via dehydration synthesis forming peptide bonds
Two amino acids linked together are called dipeptides
More than 2 linked together are called polypeptides - polypeptides can be thousands of amino acids long

9. Can you draw a peptide bond?
Which two functional groups join to make the peptide bond???

10. Dehydration synthesis of a protein

11. Hydrolysis of a Protein

12. Protein Structure
Protein types include globular proteins which are usually enzymes and Fiberous proteins which usually serve for structure (eg. Hair)
Proteins Exhibit 4 “levels of structure.

13. Primary Structure
Primary Structure of a protein is it’s sequence of amino acids
Primary Structure dictates all further levels of protein structure

14. Secondary Structure
The Sequence (primary structure) causes parts of a protein molecule to fold into sheets or bend into helix shapes - this is a protein’s Secondary Structure.

15. Tertiary Structure
The protein then can compact and twist on itself to form a mass called it’s Tertiary Structure

16. Quaternary Structure
Several Proteins then can can combine and form a protein’s Quaternary Structure
Various conformations are usually caused by the formation of hydrogen or disulfide bonds.
PH, changes or heat can disrupt these bonds, permanently denaturing the protein.