Presentation is loading. Please wait.

Presentation is loading. Please wait.

7.5 Proteins. 7.5.1 Explain the four levels of protein structure, indicating the significance of each level. 1°- sequence of amino acids in the chain.

Similar presentations


Presentation on theme: "7.5 Proteins. 7.5.1 Explain the four levels of protein structure, indicating the significance of each level. 1°- sequence of amino acids in the chain."— Presentation transcript:

1 7.5 Proteins

2 7.5.1 Explain the four levels of protein structure, indicating the significance of each level. 1°- sequence of amino acids in the chain 2°- coils; H bonds; collagen, keratin have repeated sequences so have lots coils α-helix: hair, wool, horns, feathers β-pleated sheet: silk

3 7.5.1 Explain the four levels of protein structure, indicating the significance of each level. 3°- helix folding; R groups interact: hydrophobics cluster together on inside, hydrophilics cluster on outside, disulfide bridges between S of 2 R groups (cov bond), ions may be cofactors

4 7.5.1 Explain the four levels of protein structure, indicating the significance of each level. 4°- different polypeptides combine w/H bonds, +/- attractions, hydrophobic forces, and/or disulfide bridges; common in large globular proteins (hemoglobin2 α chains, 2 β chains) conjugated proteins - binding of prosthetic group: each chain also has a Heme group, contains Fe (not a polypeptide) chlorophyll, electron transport chain enzymes are other examples

5 7.5.2 Outline the difference between fibrous proteins & globular proteins, with reference to two examples of each protein type. FibrousGlobular ShapeLongTightly folded SolubilityInsoluble in waterSoluble in water Main level of organization 2° is most important3° is most important FunctionStructural (they ARE something) Functional (they DO something) ExamplesCollagen, keratin, myosin Hemoglobin, enzymes, antibodies, hormones

6 7.5.3 Explain the significance of polar and non- polar amino acids. 20 common amino acids 8 w/non-polar R groups –Insoluble in water –Cluster center (4° structure) More non-polar AAs less soluble in water Cell membrane (phospholipid bilayer): polar on outside, non on inside –Protein situated with hydrophilic portions to outside of membrane, hydrophobic sections to center

7 7.5.4 State four functions of proteins, giving a named example of each: Structure: collagen (fibrous, structural ptn) builds tendons & in skin Enzymes: all are globular –starch –amylase maltose Transport: hemoglobin (globular, conjugated); readily, reversibly binds Oxygen b/c of heme group

8 7.5.4 State four functions of proteins, giving a named example of each: Hormones: some are ptns (some are steroids) –Insulin Contractile: muscle contractions (actin, myosin) Defense: antibodies/immunoglobulins for defense against antigens

9

10

11

12

13

14

15

16

17

18

19

20

21

22

23

24

25


Download ppt "7.5 Proteins. 7.5.1 Explain the four levels of protein structure, indicating the significance of each level. 1°- sequence of amino acids in the chain."

Similar presentations


Ads by Google