1. Protein

2. Macromolecules: Proteins
Proteins taken in as food (meat, dairy, eggs, beans, nuts) are different than our proteins.
They must be broken down into amino acids by adding water. Recall Carbohydrates and Lipids
The process is…
Hydrolysis.
To build proteins water must be removed in the process of….
Dehydration Synthesis.

3. Proteins: CHON(S) peptide bond
Proteins are large complex polypeptides.
Needed for structure: muscles, skin, cell membranes, and enzymes
Made of amino acids
Amino acids are joined by peptide bonds
A string of peptides is also called a polypeptide
peptide bond

4. Proteins: Structure Amino acids have three parts:
The 20+ amino acids differ only in their R-group

5. Generalized Formula for Amino AcidH
Acid group
R C COOH
NH2
Rest of the molecule
Amino group

6. Amino Acid Groups H
NH2 = N H O
Double Bond
COOH = C O H

7. Macromolecules: Proteins
Peptide bonds join amino acids when dehydration synthesis occurs.
An OH from the acid group of one amino acid joins to an H from the amino group of the other amino acid.
A water molecule is formed, and a C-N bond is formed between the two amino acids.
The C-N bond is called a peptide bind.
Dipeptide: 2 amino acids joined
Polypeptide: 3 or more amino acids joined.

8. Dehydration Synthesis
Prentice Hall, Biology

9. Proteins: Structure The protein you end up with depends on:
which amino acids were chosen,
their order (sequence), and
how many of each
Who decides?
The DNA

10. Proteins: Structure Valine Leucine Glutamic Acid
Compare 3 amino acids:
Valine
Leucine
Glutamic Acid

12. Proteins: Enzymes
Enzymes are proteins that act as a catalyst. (Catalysts are substances that increase the rate of a chemical reaction.)
Enzymes are not used up or changed by a reaction.
Enzymes are specific in their actions.
Enzymes work best under specific conditions.

13. Category 2
Category 1
Let’s Review
What is the name of this unit?
Category 3
Category 4