Part 1 carbohydrates prepared by dr a riasi isfahan university of technology reference
This presentation is the property of its rightful owner.
Sponsored Links
1 / 51

Part 1: Carbohydrates Prepared by: Dr A. Riasi ( Isfahan University of Technology ) Reference: PowerPoint PPT Presentation


  • 95 Views
  • Uploaded on
  • Presentation posted in: General

Isfahan University of Technology. Advance Biochemistry. Part 1: Carbohydrates Prepared by: Dr A. Riasi ( Isfahan University of Technology ) Reference: Lehninger Biochemistry. Introduction. Importance of carbohydrates: Photosynthesis Dietary staple: sugar and starch

Download Presentation

Part 1: Carbohydrates Prepared by: Dr A. Riasi ( Isfahan University of Technology ) Reference:

An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -

Presentation Transcript


Part 1 carbohydrates prepared by dr a riasi isfahan university of technology reference

Isfahan University of Technology

Advance Biochemistry

Part 1:

Carbohydrates

Prepared by:

Dr A. Riasi ( Isfahan University of Technology)

Reference:

Lehninger Biochemistry


Part 1 carbohydrates prepared by dr a riasi isfahan university of technology reference

Introduction

  • Importance of carbohydrates:

    • Photosynthesis

    • Dietary staple: sugar and starch

    • Oxidation: energy-yielding pathway

    • Structural and protective elements

    • Lubricate skeletal joints

    • Recognition and adhesion between cells


Part 1 carbohydrates prepared by dr a riasi isfahan university of technology reference

Introduction (Continue)

  • Many, but not all, carbohydrates have the empirical formula (CH2O)n.

  • There are three major size classes of carbohydrates:

    • Monosaccharides

    • Oligosaccharides

    • Polysaccharides


Part 1 carbohydrates prepared by dr a riasi isfahan university of technology reference

Introduction (Continue)


Part 1 carbohydrates prepared by dr a riasi isfahan university of technology reference

Monosaccharides and Disacacharides

  • Monosaccharide characteristics:

    • Consist of a single polyhydroxy aldehyde or ketone unit.

    • Many of the carbon atoms to which hydroxyl groups are attached are chiral centers.


Part 1 carbohydrates prepared by dr a riasi isfahan university of technology reference

Monosaccharides and Disacacharides

  • Monosaccharides are colorless, crystalline solids.

  • In the open-chain form, one of the carbon atoms is double-bonded to an oxygen atom.


Part 1 carbohydrates prepared by dr a riasi isfahan university of technology reference

Monosaccharides and Disacacharides

  • Monosaccharides are aldose or ketose


Part 1 carbohydrates prepared by dr a riasi isfahan university of technology reference

Monosaccharides and Disacacharides

  • Monosaccharides with three, four, five, six, and seven carbon atoms in their backbones:

    • Triose

    • Tetroses

    • Pentoses

    • Hexoses

    • Heptoses


Part 1 carbohydrates prepared by dr a riasi isfahan university of technology reference

Monosaccharides and Disacacharides

  • The hexoses are the most common monosaccharides in nature.


Part 1 carbohydrates prepared by dr a riasi isfahan university of technology reference

Monosaccharides and Disacacharides


Part 1 carbohydrates prepared by dr a riasi isfahan university of technology reference

Monosaccharides and Disacacharides

  • All the monosaccharides except dihydroxyacetone contain one or more asymmetric carbon atoms.


Part 1 carbohydrates prepared by dr a riasi isfahan university of technology reference

Monosaccharides and Disacacharides

  • The simplest aldose, glyceraldehyde, contains one chiral center and therefore has two different optical isomers, or enantiomers.


Part 1 carbohydrates prepared by dr a riasi isfahan university of technology reference

Monosaccharides and Disacacharides


Part 1 carbohydrates prepared by dr a riasi isfahan university of technology reference

Monosaccharides and Disacacharides

  • In general, a molecule with n chiral centers can have 2nstereoisomers.

  • Glyceraldehyde has 21 = 2; the aldohexoses, with four chiral centers, have 24 = 16 stereoisomers.


Part 1 carbohydrates prepared by dr a riasi isfahan university of technology reference

Monosaccharides and Disacacharides


Part 1 carbohydrates prepared by dr a riasi isfahan university of technology reference

Monosaccharides and Disacacharides


Part 1 carbohydrates prepared by dr a riasi isfahan university of technology reference

Monosaccharides and Disacacharides


Part 1 carbohydrates prepared by dr a riasi isfahan university of technology reference

Monosaccharides and Disacacharides


Part 1 carbohydrates prepared by dr a riasi isfahan university of technology reference

Monosaccharides and Disacacharides


Part 1 carbohydrates prepared by dr a riasi isfahan university of technology reference

Monosaccharides and Disacacharides


Part 1 carbohydrates prepared by dr a riasi isfahan university of technology reference

Monosaccharides and Disacacharides


Part 1 carbohydrates prepared by dr a riasi isfahan university of technology reference

Monosaccharides and Disacacharides

  • Some sugars occur naturally in their L form:

    • L-arabinose

    • L isomers of some sugar derivatives that are common components of glycoconjugates.


Part 1 carbohydrates prepared by dr a riasi isfahan university of technology reference

Monosaccharides and Disacacharides

  • The formation of ring structures form:

    • Hemiacetals

    • hemiketals


Part 1 carbohydrates prepared by dr a riasi isfahan university of technology reference

Monosaccharides and Disacacharides


Part 1 carbohydrates prepared by dr a riasi isfahan university of technology reference

Monosaccharides and Disacacharides


Part 1 carbohydrates prepared by dr a riasi isfahan university of technology reference

Monosaccharides and Disacacharides

  • The αand βanomers of D-glucose interconvert in aqueous solution by a process called mutarotation.


Part 1 carbohydrates prepared by dr a riasi isfahan university of technology reference

Monosaccharides and Disacacharides

  • Ketohexoses also occur in αand β anomeric forms.

  • D-Fructose readily forms the furanose ring the more common anomer of this sugar in combined forms or in derivatives is β-D-fructofuranose.


Part 1 carbohydrates prepared by dr a riasi isfahan university of technology reference

Monosaccharides and Disacacharides


Part 1 carbohydrates prepared by dr a riasi isfahan university of technology reference

Monosaccharides and Disacacharides


Part 1 carbohydrates prepared by dr a riasi isfahan university of technology reference

Monosaccharides and Disacacharides

  • Two conformationsof a molecule are interconvertible without the breakage of covalent bonds

  • Two configurationscan be interconverted only by breaking a covalent bond for example, in the case of αand βconfigurations, the bond involving the ring oxygen atom.


Part 1 carbohydrates prepared by dr a riasi isfahan university of technology reference

Hexose derivatives in organisms

  • There are a number of sugar derivatives in which a hydroxyl group in the parent compound is replaced with another substituent or the carbon atom is oxidized to a carboxyl group.


Part 1 carbohydrates prepared by dr a riasi isfahan university of technology reference

Hexose derivatives in organisms

  • Different derivatives of hexoses:

    • Containing an amine group (-NH2)

    • Containing a N-acetyl group (-NH-CO-CH3)

    • Containing an acid lactic and an amine group or a N-actyl group

    • Containing a methyl group (-CH3)

    • Containing a carboxyl group (-COO-)


Part 1 carbohydrates prepared by dr a riasi isfahan university of technology reference

Hexose derivatives in organisms

  • Replacing the hydroxyl group with an amino group.


Part 1 carbohydrates prepared by dr a riasi isfahan university of technology reference

Hexose derivatives in organisms

  • Bacterial cell walls contain a derivative of glucosamine.

OH

OH


Part 1 carbohydrates prepared by dr a riasi isfahan university of technology reference

Hexose derivatives in organisms

  • The substitution of a hydrogen hydroxyl group at C-6 of L-galactose or L-mannose produces L-fucose or L-rhamnose, respectively.


Part 1 carbohydrates prepared by dr a riasi isfahan university of technology reference

Hexose derivatives in organisms

  • Oxidation of the carbonyl (aldehyde) carbon of glucose, galactose, or mannose forms the corresponding aldonic acids:

    • Gluconic acid

    • Galactonic acid

    • Manonic acid


Part 1 carbohydrates prepared by dr a riasi isfahan university of technology reference

Hexose derivatives in organisms

  • Monosaccharides can be oxidized by mild oxidizing agents such as ferric (Fe 3+) or cupric (Cu2+) ion.


Part 1 carbohydrates prepared by dr a riasi isfahan university of technology reference

Hexose derivatives in organisms

  • Oxidation of the carbon at the other end of the carbon chain (C-6) of glucose, galactose, or mannose forms the corresponding uronic acid:

    • Glucuronic

    • Galacturonic

    • Mannuronic acid


Part 1 carbohydrates prepared by dr a riasi isfahan university of technology reference

Hexose derivatives in organisms

  • The acidic glucose derivatives are:


Part 1 carbohydrates prepared by dr a riasi isfahan university of technology reference

Hexose derivatives in organisms

  • In addition to previous mentioned acidic hexose derivatives, there is a nine-carbon acidic sugar:


Part 1 carbohydrates prepared by dr a riasi isfahan university of technology reference

Hexose derivatives in organisms

  • In bacterial systems an enzyme uses a mannose derivative as a substrate, inserting three carbons from pyruvate into the resulting sialic acid structure.


Part 1 carbohydrates prepared by dr a riasi isfahan university of technology reference

Hexose derivatives in organisms

  • In the synthesis and metabolism of carbohydrates, the intermediates are very often not the sugars themselves but their phosphorylated derivatives.


Part 1 carbohydrates prepared by dr a riasi isfahan university of technology reference

Disaccharides contain a glycosidic bond

  • Disaccharides consist of two monosaccharides joined covalently by an O-glycosidic bond.


Part 1 carbohydrates prepared by dr a riasi isfahan university of technology reference

Disaccharides contain a glycosidic bond


Part 1 carbohydrates prepared by dr a riasi isfahan university of technology reference

Hexose derivatives in organisms

  • Nonreducing disaccharides are named as glycosides; in this case, the positions joined are the anomeric carbons.


Part 1 carbohydrates prepared by dr a riasi isfahan university of technology reference

Hexose derivatives in organisms


Part 1 carbohydrates prepared by dr a riasi isfahan university of technology reference

Hexose derivatives in organisms

  • Trehalose, Glc(1 1)Glc is a disaccharide of D-glucose that, like sucrose, is a nonreducing sugar.

  • It is a major constituent of the circulating fluid (hemolymph) of insects, serving as an energy storage compound.


  • Login