1. Proteins

2. Examples of Proteins
Horns
Spider Webs
Hair
Egg Whites

3. Hair

4. Nails
Muscles
Enzymes

5. Functions of Proteins What do proteins do?
Provide Structural Support
Example: Collagen in Skin
Make up Antibodies in your Immune System
Transport
Example: Hemoglobin carries Oxygen

6. Proteins: How They’re Made
Made up of C, H, O, N, and sometimes S

7. Proteins: How They’re Made
What are the monomers of a protein?
Amino Acids
How many amino acids are there? 20
What are the parts of an amino acid?

8. Amino Acids

9. With Peptide Bonds (in dehydration synthesis)
Polymers
How are amino acids joined?
With Peptide Bonds (in dehydration synthesis)
Two amino acids together are called a
Dipeptide
Many amino acids are called a
Polypeptide

10. Polymers
Which two groups of the amino acid form a peptide bond?

11. Polypeptide
Amino Acid
Peptide Bond

12. Proteins Does the order of the amino acids in a protein matter? Why?
The order of the amino acids affects the SHAPE
Why is the shape of the protein important?
The shape determines the FUNCTION!
Why?

13. Denaturing Proteins
Two changes cause a change in the shape of the protein…this is known as DENATURATION.
So if the shape changes, what’s affected?
The Function of the Protein!
Other Causes of Protein Denaturation
salt concentration and environmental factors

14. What are some examples of Denatured Proteins?
Raw Egg vs. Cooked Egg
Raw Meat Vs. Grilled Meat
How is the consistency of raw vs. cooked different?

15. A type of protein that speeds up metabolic (chemical) reactions.
ENZYMES
aka: Catalysts
What is an enzyme?
A type of protein that speeds up metabolic (chemical) reactions.

16. What is needed to start a reaction?
Activation energy
Energy absorbed
reactant
Energy released
Products

17. Why is the activation energy lower?
Energy absorbed
Energy released
reactant
Products
Activation energy
A Catalyst was added!
Enzymes lower the activation energy

18. Comparing Reactions
Which line would represent a reaction with an enzyme present?
Without an enzyme
Energy absorbed
Reactant
Products
Energy released

19. How Do Enzymes Work? Enzymes work like a lock and key.
Specific enzymes work with specific substrates.
enzyme
Use the analogy of enzymes as a lock and key.
Explain that substrates are reactants.
Substrate (key) must fit exactly into the active site of and enzyme (lock), just like only specific keys fit certain locks.
substrate

20. a substance on which an enzyme acts during a chemical reaction
What’s a Substrate?
a substance on which an enzyme acts during a chemical reaction
*enzymes act only on specific substrates

21. The substance is formed in a chemical reaction
What is a product?
The substance is formed in a chemical reaction

22. Enzymes and Active Sites
What is an Active Site?
The site on an enzyme that attaches to the substrate
Is the active site the same for all enzymes and substrates?
NO! Only a certain substrate fits into a particular active site

23. Enzymes Activity Why is this not good?
Changes in pH and temperature can affect the shape of an enzyme.
What will happen if the shape changes?
The enzyme can be denatured
Why is this not good?
Any factor that changes the shape of an enzyme can affect the enzyme’s activity

24. Enzymes in our Body Amylase Enzyme found in our saliva
Breaks down some starches into glucose molecules
So digestion of food occurs in the mouth before it reaches the stomach
Pepsin
First animal enzyme to be discovered
Digestive protease in stomach that works with HCl acid to degrade food proteins into peptides