Bi111Chapter5PP

Catalyze speed reachons any given animal

Info iconThis preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: needed in diet? •  1.energy source 2.digested to a.a., reassembled as proteins for use in body •  EssenHal a.a.? •  Complete protein? Amino group carboxyl group Carboxyl group R group 7 PolypepHdes = chains of a.a. •  Amino acid linked by pep*de (covalent) bonds thru ______ (dehydraHon/hydrolysis) rxn. –  Polymers built from combo of 20 diff. amino acids –  vary- few to 1000’s a.a. long α carbon Peptide bond Amino group (a) •  PepHde bond is 1 type of Side chains covalent (polar or non?) Backbone •  carboxyl + amino Peptide bond (b) Amino end (N-terminus) Carboxyl group Carboxyl end (C-terminus) Fig. 5- 18 •  Amino acids may be nonpolar, polar or charged •  Detemined by R groups, collecHvely give proteins’ Nonpolar properHes Fig. 5-17a Glycine (Gly or G) Methionine (Met or M) Alanine (Ala or A) Valine (Val or V) Phenylalanine (Phe or F) Leucine (Leu or L) Tryptophan (Trp or W) Isoleucine (Ile or I) Proline (Pro or P) 8 Fig. 5- 17b Polar Serine (Ser or S) Threonine (Thr or T) Cysteine Tyrosine (Cys or C) (Tyr or Y) Asparagine Glutamine (Asn or N) (Gln or Q) Fig. 5- 17c Electrically charged Acidic Aspartic acid Glutamic acid (Glu or E) (Asp or D) Basic Lysine (Lys or K) Arginine (Arg or R) Histidine (His or H) Protein structure and funcHon •  Diff. b/w polypepHde & protein? –  Protein: >1 polypepHde chains twisted, folded, and coiled into unique shape •  Protein: 1→4 levels of structure (primary→quaternary) –  Specific order of amino acids largely determines shape, but very difficult to predict final structure (several possibiliHes) –  hep://fold.it/portal/ –  “gaming for a cure” http://www.sciencedaily.com/releases/ 2011/09/110918144955.htm 9 •  Protein shape = its funcHon Compare to Fig. 5- 21 Four levels of protein structure (Fig 5.21) Primary Structure •  1. Primary: unique sequence of amino acids (backbone) 1 5 +H 3N Amino end 10 Amino acid subunits 15 20 25 2. Secondary: coils and folds due to H- bonding paeerns b/w backbone consHtuents Secondary Structure β pleated sheet Examples of amino acid subunits α helix 10 Fig. 5- 21f 3. Ter*ary: overall shape due to interacHons among R groups (side chains) - Includes ionic bonds, disulfide bridges, hydrophobic interacHons, etc. Hydrophobic interac*ons and van der Waals interac*ons PolypepHde backbone Hydrogen bond Disulfide bridge Ionic bond Tertiary Structure 4. Q...
View Full Document

This note was uploaded on 09/30/2013 for the course BIO 111 taught by Professor Jefferyray during the Fall '13 term at North Alabama.

Ask a homework question - tutors are online