1. Proteins

2. What are proteins? Contain the elements C, H, O and N
Nitrogen gives the protein its specific characteristics as a protein
The main function of protein is to provide body with materials for building and repairing body tissues

3. Structure of Protein
Proteins are made of smaller building blocks called amino acid
There are only 20 amino acids used to make proteins in our body, they can create unlimited combinations of proteins

4. Structure of Amino acid

5. Basic Structure of Amino Acid
All amino acids have the ending -ine
All amino acids have carboxyl group (contains COOH or COO-)
All amino acids have amino group (contains NH2 or NH3 +

6. Basic Structure of Amino Acid
The only difference between amino acids is their R group or Variable group
The R group gives each amino acid its specific, individual traits

7. Structure of Amino acid

8. Can you identify the carboxyl group, the amino group, the R group and the central carbon?

9. Proteins Proteins are made of multiple amino acids linked together
To link 2 amino acids, a peptide bond is formed

10. Formation of peptide bond
Proteins are formed by joining the carboxyl group of one amino acid to the amino group of another amino acid.
The bond formed between two amino acids is called a peptide bond

11. Peptide bond
Peptide bonds are always between NH and C=O

12. Where are the peptide bonds?

13. Classification of Proteins
Dipeptide: 2 amino acids joined by a peptide bond
Tripeptide:
Polypeptide:

14. This procedure is called dehydration synthesis

15. Peptide Bond Break Down
If polypeptide can be formed through Dehydration synthesis, then polypeptide can be broken by ________________________

16. Amino Acids Each amino acid is different
Some “like” water: they will dissolve in it
They are called: Hydrophilic Amino Acids
Some “fear” water: they will separate from it
They are called: Hydrophobic Amino Acids

17. Protein Folding

18. It’s the SHAPE that matters!
Proteins do their jobs, because of their shape
Unfolding a protein destroys its shape
wrong shape = can’t do its job
unfolding proteins = “denature”
Factors that affect proteins’ shape:
temperature
pH (acidity)
unfolded “denatured”
folded

19. Protein Levels of Organization
Primary Structure: the linear sequence of amino acids in a protein chain
Secondary Structure: the folding or coiling of the protein chain
Tertiary Structure: the actual 3D shape of the protein
Quaternary Structure: a complex of 3D shaped proteins joined together