2. PROTEINS AND NUCLEIC ACIDS

3. Proteins  Function: Communication Hormones: signals from one body system to another insulin Structure muscle Antiodies protect against germs Enzymes help chemical reactions Many more

4. collagen (skin) Proteins Examples  muscle  skin, hair, fingernails, claws collagen, keratin  pepsin digestive enzyme in stomach  insulin hormone that controls blood sugar levels insulin pepsin

5. Proteins  Building block = amino acid amino acid – amino acid – amino acid – amino acid – —N——N— H H H | —C— | C—OH || O variable group amino acids  21 different amino acids There’s 21 of us… like 21 different letters in an alphabet! Can make lots of different words

6. Amino acid chains  Proteins  amino acids chained into a polymer  Each amino acid is different  some “like” water & dissolve in it  some “fear” water & separate from it amino acid

7. Water-fearing amino acids  Hydrophobic  “water fearing” amino acids  try to get away from water in cell  the protein folds

8. Water-loving amino acids  Hydrophillic  “water loving” amino acids  try to stay in water in cell  the protein folds

9. pepsin For proteins: SHAPE matters!  Proteins fold & twist into 3-D shape  that’s what happens in the cell!  Different shapes = different jobs collagen hemoglobin growth hormone

10. It’s SHAPE that matters!  Proteins do their jobs, because of their shape  Unfolding a protein destroys its shape  wrong shape = can’t do its job  unfolding proteins = “denature” temperature pH (acidity) folded unfolded “denatured”

11. NUCLEIC ACIDS 2006-2007

12. proteins DNA Nucleic Acids  Function:  genetic material stores information genes blueprint for building proteins DNA  RNA  proteins transfers information blueprint for new cells blueprint for next generation

13. Nucleic Acids  Examples:  RNA (ribonucleic acid) single helix  DNA (deoxyribonucleic acid) double helix  Structure:  monomers = nucleotides RNADNA

14. Nucleotides  3 parts  nitrogen base (C-N ring)  pentose sugar (5C) ribose in RNA deoxyribose in DNA  phosphate (PO 4 ) group