1. Welcome Back! February 27, 2012 Sit in any seat for today. You will have assigned seats tomorrow Were you absent before the break? Plan on coming to tutorial today or tomorrow to makeup the test (from Thursday), it must be completed by Tuesday in tutorial.

2. Open Logbook…do you have an entry from Friday before break? Entry10: Proteins Beginning Ideas

3. Make an entry- Entry 11. Proteins: Amino Acids in 3 D- 2/27/12

4. 2 Types of Proteins 1) Structural – proteins that form physical parts. Examples – -keratin (hair and nails) -actin (muscle) -microtubules (cell membrane skeletons) - gelatin - collagen

5. 2) Functional – Proteins that have activity Examples- -Hormones – used for signaling -Defensive – antibodies that recognize foreign invaders -Transport – Carrier proteins!!! -Enzymes – used for chemical reaction - Hemoglobin – found on RBC and carry oxygen

6. Protein Shape Determines Function Example – Fibrous proteins are long and thin, and are used for structure

7. What will we learn today? HOW is the shape of a protein determined?

8. Proteins are made of chains of amino acids What are amino acids? Link to amino acid 3-D models

9. H2NH2N Amino group C Side chain R H C O OH Carboxyl group Non-ionized form There are 20 different amino acids. All have the same general form.

10. CC O O–O– H H3N+H3N+ H Glycine (G) Gly CC O O–O– H H3N+H3N+ CH 3 Alanine (A) Ala CC O O–O– H H3N+H3N+ CH H3CH3C CH 3 Valine (V) Val CC O O–O– H H3N+H3N+ CH 2 H3CH3C CH 3 Leucine (L) Leu CH CC O O–O– H H3N+H3N+ Isoleucine (I) Ile CH 3 CH 2 H3CH3C Side chains contain carbon and/or hydrogen C O O–O– C CH 2 H2CH2C H2N+H2N+ H Proline (P) Pro Each amino acid has a different side chain.

11. C H3N+H3N+ CH 2 H C O O–O– Phenylalanine (F) Phe C H3N+H3N+ CH 2 H C O O–O– Tyrosine (Y) Tyr OH C H3N+H3N+ CH 2 H C O O–O– NH Tryptophan (W) Trp Side chains contain ring structures Each amino acid has a different side chain.

12. CH 3 CH 2 S CC H3N+H3N+ H O O–O– Methionine (M) Met SH CH 2 CC H3N+H3N+ H O O–O– Cysteine (C) Cys Side chains contain sulfur Each amino acid has a different side chain.

13. OH CH 2 CC H3N+H3N+ H O O–O– Serine (S) Ser Threonine (T) Thr CH CC H3N+H3N+ H O O–O– CH 3 HO Side chains contain hydroxyl functional groups Each amino acid has a different side chain.

14. C CH 2 CC H3N+H3N+ H O O–O– H2NH2N O Asparagine (N) Asn CH 2 CC H3N+H3N+ H O O–O– C O H2NH2N Glutamine (Q) Gln Side chains contain amino functional groups Each amino acid has a different side chain.

15. CH 2 C C H3N+H3N+ H O O–O– NH + NH Histidine (H) His CH 2 CC H3N+H3N+ H O O–O– + NH 3 CH 2 Lysine (K) Lys Basic side chains CH 2 C C H3N+H3N+ H O O–O– NH C + NH 2 NH 2 Arginine (R) Arg Each amino acid has a different side chain.

16. CH 2 CC H3N+H3N+ H O O–O– C O–O– O Aspartate (D) Asp Acidic side chains CH 2 CC H3N+H3N+ H O O–O– C O–O– O Glutamate (E) Glu Each amino acid has a different side chain.

17. H HHHHHHOOOHHOHHO NCCNNCCCC H CH 3 CH 2 OH N-terminus NCC CH 2 C O OH CH 2 NCC CH CH 3 H3CH3C CH 2 OH HHO NCC HHO NCC H HO NC C CH 2 SH OH C-terminus H2NH2N H H C C O OH Carboxyl group H2NH2N H CH 3 CC O OH Amino group H2NH2N H H C O C NC C H H CH 3 OH O Peptide bond +H2OH2O H2NH2N GlyAlaSer Asp N-terminus 21354678 PheValTyrCys C-terminus COOH + Proteins are chains of amino acids

18. Amino Acids Model activity Peptides are chains of amino acids and sometimes used as another word for protein. Follow the instructions of your teacher to build peptides using the paper amino acid models for questions #1-4. Then join your chain with another groups chain to form an 8 amino acid chain for #5