Chapter 14 Amino Acids

1. Chapter 14 Amino Acids 14.1-14.4 By: Alexa & Bethany

2. 14.1 What are the many functions of proteins? • Proteins are the most important biological compounds • Functions:-structure for animals, chief constituents of skin, hair, bones, and nails-catalysis: proteins called enzymes are used to help speed up reactions

3. Functions (cont’d) -movement: muscles are made up of proteins which help us move-transportation: can be used in transportation. for example the protein hemoglobin, in blood, carries oxygen from lungs to cells and carbon dioxide from cells to lungs

4. functions -hormones: many hormones are made up of proteins such as insulin-protection: if unfamiliar proteins enter the body proteins called antibodies protect you from these foreign intruders. They fight disease and proteins called fibrinogen are used in blood clotting

5. more functions.. -storage- store materials , similar to the way starch and glycogen store energy-regulation: some proteins control expression of genes and regulate the kinds of proteins made in certain cells • two types of proteins: fibrous proteins and globular proteins

6. Fibrous Proteins • Insoluble in water • Used for structural purposes

7. Globular Proteins • More or less soluble in water • Used for non-structural purposes

8. 14.2 What are amino acids? • Organic compounds that contain an amino group and carboxyl group • Proteins are made up of amino acid chains • There are 20 common amino acids, alpha amino acids, in nature are used to make up proteins

9. 14.2(cont’d) • The R group helps us classify amino acids as either non-polar, polar but neutral, acidic, or basic • Non-polar chains repel water(hydrophobic) • Polar but neutral, acidic, and basic all attract water (hydrophilic)

10. 14.3 what are zwitterions? • Compounds that have a positive charge on one atom and a negative charge on another atom • Amino acids are zwitterions -solids with high melting points -soluble in water

11. 14.3 (cont’d) • There is no pH where an amino acid has no ionic character • pH is called the isoelectric point • Every amino acid has a different isoelectric point

12. 14.4 what determines the characteristics of Amino Acids? • The side of the chain is responsible for characteristics of molecules • Amino acids have acidic and basic properties

13. Properties ex: • -two amino acids, glutamic acid and aspartic acid, have carboxyl groups present in their side chain along with the one already present in amino acids • -because of the carboxylate groups on the side chains of these two amino acids they are negatively charged at a neutral pH

14. Phenylanine, tryptophan, and tyrosine • Have armotic rings in their side chains • Allow for location and measurement of proteins • Important physiologically, key precursors to neurotransmitters

15. Phenylanine, tryptophan, and tyrosine • Tryptphan is converted to serotonin (5-hydroxytryptamine) • Low levels of serotonin are associated with depression