1 / 20

What will we learn today?

What makes an enzyme specific to one type of reaction (in other words, what determines the function of a protein)? SHAPE determines the function of a protein and makes enzymes specific to one reaction How does heating (boiling) affect the ability of an enzyme to perform its function?

iokina
Download Presentation

What will we learn today?

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. What makes an enzyme specific to one type of reaction (in other words, what determines the function of a protein)? • SHAPE determines the function of a protein and makes enzymes specific to one reaction • How does heating (boiling) affect the ability of an enzyme to perform its function? • Heating/boiling denatures enzymes (unfolds them) and makes them lose their function

  2. What will we learn today? HOW is the shape of a protein determined? WHY does heating/boiling denature enzymes and make them lose their function? Also: • What makes hair straight or curly and how do perms work? • Why is it important to eat different types of food to supply our protein needs?

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

  4. There are 20 different amino acids. All have the same general form. H O C C H2N Carboxyl group Amino group OH R Side chain Non-ionized form

  5. Each amino acid has a different side chain. H H H H H H O O O O O O C C C C C C C C C C C C H3N+ H2N+ H3N+ H3N+ H3N+ H3N+ O– O– O– O– O– O– CH CH2 H3C CH CH3 H H2C CH2 H3C CH2 CH3 CH CH2 CH3 H3C CH3 Alanine (A) Ala Isoleucine (I) Ile Glycine (G) Gly Valine (V) Val Leucine (L) Leu Proline (P) Pro These side chains contain only carbon and/or hydrogen

  6. Each amino acid has a different side chain. H H H O O O H3N+ H3N+ H3N+ C C C C C C O– O– O– CH2 CH2 CH2 NH OH Phenylalanine (F) Phe Tyrosine (Y) Tyr Tryptophan (W) Trp Side chains contain ring structures

  7. Each amino acid has a different side chain. H H O O H3N+ H3N+ C C C C O– O– CH2 CH2 CH2 SH S CH3 Methionine (M) Met Cysteine (C) Cys Side chains contain sulfur

  8. Each amino acid has a different side chain. H H O O H3N+ H3N+ C C C C O– O– CH2 CH HO CH3 OH Threonine (T) Thr Serine (S) Ser Side chains contain hydroxyl [OH] functional groups

  9. Each amino acid has a different side chain. H H O O H3N+ H3N+ C C C C O– O– CH2 CH2 C CH2 O H2N C O H2N Asparagine (N) Asn Glutamine (Q) Gln Side chains contain amino [NH2] functional groups

  10. Each amino acid has a different side chain. H H H O O O H3N+ H3N+ H3N+ C C C C C C O– O– O– CH2 CH2 CH2 NH CH2 CH2 +NH CH2 CH2 CH2 NH +NH3 +NH2 C NH2 Arginine (R) Arg Histidine (H) His Lysine (K) Lys Basic side chains

  11. Each amino acid has a different side chain. H H O O H3N+ H3N+ C C C C O– O– CH2 CH2 C CH2 O– O C O– O Aspartate (D) Asp Glutamate (E) Glu Acidic side chains

  12. Proteins are chains of amino acids H H O H H H O O O N C H2N + H2N H2N C C C + H2O C C C C OH OH OH Amino group H Peptide bond CH3 CH3 H Carboxyl group C-terminus N-terminus H O H H O H H O H H O H H O H H O H H O H H O H OH C H N C C N C C N C C N C C N C C N C C N C C N C CH3 CH2 CH2 H CH2 CH2 CH CH2 H3C CH3 OH OH C SH O OH N-terminus C-terminus COOH H2N Asp Phe Val Tyr Cys Gly Ala Ser 1 2 3 4 5 6 7 8

  13. Amino Acid sequence determines the 3-D protein shape • Interactions between amino acids cause folding and bending of the chain Examples: • positive (+) and negative (-) parts of amino acids are attracted to each other. • hydrophobic regions are attracted to each other • Folding http://www.stolaf.edu/people/giannini/flashanimat/proteins/hydrophobic%20force.swf • Structure levels http://www.stolaf.edu/people/giannini/flashanimat/proteins/protein structure.swf

  14. Figure 3.11a Interactions that determine the structure of proteins H C O N Hydrogen bond between peptide groups O H3C CH3 (CH2)4 CH2CH NH3+ CHCH2 –O CCCH2 H3C CH3 OH CH2 O C Ionic bond Hydrogen bond between side chain and peptide group Hydrophobic interaction O H CH2 OH N CH2C CH2 S S CH2 H Disulfide bond Hydrogen bond between two side chains

  15. Figure 3.11b Tertiary structures are diverse. A tertiary structure composed mostly of a-helices A tertiary structure composed mostly of b-pleated sheets A tertiary structure rich in disulfide bonds

  16. Paper polypeptides 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.

  17. Straight, curly, and “permed” hair

  18. Explain the connection between the order of the amino acids and the shape of the protein. Why did the boiled lactase not work any more? (base your answer on the paper model)

  19. ESSENTIAL AMINO ACIDS

  20. Essential amino acids and nutrition • Consider why protein is needed and what amino acids and proteins are used for in the body. Describe the symptoms you would expect a person with protein deficiency to have. • Look at Table 1. Which amino acids does corn lack (not have)? Which amino acids do beans and legumes lack (not have)? • Vegans are vegetarians that do not eat any food from animals, including milk and eggs. Why must vegans combine foods from a variety of plant sources to avoid protein deficiency (for example rice and beans instead of only beans)? • A new protein supplement for athletes and weightlifters advertises that it is the best because it is made of “100% natural organic corn protein”. Why would this not be a good product for athletes and weightlifters?

More Related