Proteins

1. Proteins

2. Proteins are made of smaller biomolecules called amino acids • Amino Acids are small compounds that contain both a carboxylic acid end and an amino end • There are 20 different amino acids

5. Peptides • Amino acids can join together to form a peptide bond • A condensation reaction occurs as the amino and carboxylic acid ends join

7. So peptides are polymers of amino acids • 2 amino acid form a dipeptide • 3 amino acids form a tripeptide • And so on…

8. Proteins – polypeptides that have a biological function • Most proteins range from several amino acids to several thousand in length

9. The formula for a proteins could be: • C1864H3012O576N468S21 • This protein weighs 42,290 g/mol

10. Proteins exist everywhere in the body either as solids or liquids • Soild: hair, fingernails, bones • Liquid: hemoglobin, antibodies

11. Protein structure • There are many factors that determine protein structure • Structure can be divided into 4 levels • primary • secondary • tertiary • quaternary

12. Primary structure • This is the first level of structure and it is just the sequence of amino acids • Primary structure is the linear sequence of amino acids

13. Secondary structure • Secondary structure comes from the arrangement of the primary structure • Secondary structure is where certain parts of the protein will begin forming basic structures

14. Secondary formations • Secondary structure has two basic forms • α-helix • β-sheet

15. α-helix • This structure looks like a spiral and is formed from the smaller amino acids, glycine, proline, alanine, etc. • The protein forms loops that stack together but do not fold back on themselves

16. β-sheet • This structure looks like a flat sheet and is formed from the nonpolar amino acids • β-sheets require the protein to fold back on itself in a zigzag pattern

17. Tertiary structure • Tertiary structure involves the secondary structures interacting with themselves or other parts of the primary structure

18. Quaternary structure • Tells us how the tertiary structure interacts with other tertiary structures

20. Protein folding • Protein folding is very important to the function of a protein • A misfolded protein will usually not work at all or will work very poorly

21. Diseases • Many diseases occur from the misfolding of a protein • Misfolding is usually from one or more amino acids being incorrect in the protein

22. Sickle-cell anemia

23. Sickle-cell anemia occurs when a single amino acid is accidently changed for another • This causes a very large change in the quaternary structure even though the other 300 amino acids are all correct

24. Cancer • Involves protein misfolding for one more more proteins in a cell