1 / 18

CARBOHYDRATES

CARBOHYDRATES. Bodies main energy source CH 2 O Only plants synthesise carbohydrates Starch , Cellulose ( polysaccharides ) Lactose , sucrose ( dissaccharides ) Glucose , fructose ( monosaccharides ). Monosaccharides. (CH 2 O) n where n=3 to 9

livia
Télécharger la présentation

CARBOHYDRATES

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. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. CARBOHYDRATES • Bodiesmainenergysource • CH2O • Onlyplantssynthesisecarbohydrates • Starch, Cellulose (polysaccharides) • Lactose, sucrose (dissaccharides) • Glucose, fructose (monosaccharides)

  2. Monosaccharides • (CH2O)nwhere n=3 to 9 • Aldehydesorketonescontaining a carbonylgroup and at least 2 hydroxylgroups • Hexoses (glucose, galactose, fructose)

  3. Pentoses • Contain 5 carbonatoms • Ribose

  4. Properties of Mono and di-saccharides • Low molar masses • Sweet • Soluble in water • Crystallinesolids • Reducingsugars (aldehydegroupoxidised)

  5. Structure of Glucose

  6. Interconversion of α and βglucose

  7. Straightchain and cyclicfructose

  8. Condensation of Monosaccharides

  9. Disaccharideformation • Β-glucose + β-galactose -----> lactose • α-glucose + α-glucose -------> maltose • α-glucose + β-fructose ------> sucrose

  10. Polysaccharides • Numerousmonosaccharideunits • Largemasses • Notsweet, non-reducing, insoluble • Starchisplantstoreforglucose • Twoforms : • Amylose (water soluble) • Amylopectin (water insoluble)

  11. Amylose • α-1,4 glycosidiclinkages

  12. Amylopectin • α-1,4 glycosidiclinkages as well as α-1,6 glycosidiclinkages

  13. Glycogen • More highlybranchedthanamylopectinbutalso has α-1,4 glycosidiclinkages as well as α-1,6 glycosidiclinkages

  14. Cellulose • Linear • Made up of β-glucoseunitswithallglycosidiclinkages in the 1, 4-position • Extensivehydrogenbondingbetweenchains • Strength, rigidity • Insoluble

  15. MajorFunctions of Carbohydrates • EnergySource • Energy Reserve (e.g. glycogen) • Precursor of otherBiologicallyImportantMolecules (e.g. anticoagulants, components of nucleicacids)

  16. DietaryFibre • Plant material • Cannot be digestedbyhumans • Parts of fruits, vegetables, grains • May be digestedby bacteria in gut • Cellulose • Lignin • Pectin

  17. Importance of High FibreDiet • Constipation and Diverticulosis • Irritable bowelsyndrome • Obesity • Crohn´sDisease • Haemorrhoids

  18. Reading and questions • Pleasereadpages 331 to 334, allaboutcarbohydrates. • Takeyourown notes. • Make a mindmap. • Can youanswerthequestions in theorange boxes (B.3.1 etc) ? • Nowanswerquestions 9 to 16 on page 359.

More Related