Chapter25 - Chapter 25. Biomolecules: Carbohydrates Based...

Info iconThis preview shows pages 1–9. Sign up to view the full content.

View Full Document Right Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

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

Unformatted text preview: Chapter 25. Biomolecules: Carbohydrates Based on McMurrys Organic Chemistry , 6 th edition 2003 Ronald Kluger Department of Chemistry University of Toronto Based on McMurry, Organic Chemistry, Chapter 25, 6th 2 Importance of Carbohydrates Distributed widely in nature Key intermediates of metabolism (sugars) Structural components of plants (cellulose) Central to materials of industrial products: paper, lumber, fibers Key component of food sources: sugars, flour, vegetable fiber Contain OH groups on most carbons in linear chains or in rings Based on McMurry, Organic Chemistry, Chapter 25, 6th 3 Chemical Formula and Name Carbohydrates have roughly as many Os as Cs (highly oxidized) Since Hs are about connected to each H and O the empirical formulas are roughly (C(H 2 O)) n Appears to be carbon hydrate from formula Current terminology: natural materials that contain many hydroxyls and other oxygen-containing groups Based on McMurry, Organic Chemistry, Chapter 25, 6th 4 Sources Glucose is produced in plants through photosynthesis from CO 2 and H 2 O Glucose is converted in plants to other small sugars and polymers (cellulose, starch) Dietary carbohydrates provide the major source of energy required by organisms Based on McMurry, Organic Chemistry, Chapter 25, 6th 5 25.1 Classification of Carbohydrates Simple sugars (monosaccharides) can't be converted into smaller sugars by hydrolysis. Carbohydrates are made of two or more simple sugars connected as acetals (aldehyde and alcohol), oligosaccharides and polysaccharides Sucrose (table sugar): disaccharide from two monosaccharides (glucose linked to fructose), Cellulose is a polysaccharide of several thousand glucose units connected by acetal linkages (aldehyde and alcohol) A disaccharide derived from cellulose Based on McMurry, Organic Chemistry, Chapter 25, 6th 6 Aldoses and Ketoses aldo- and keto- prefixes identify the nature of the carbonyl group - ose suffix designates a carbohydrate Number of Cs in the monosaccharide indicated by root (-tri-, tetr-, pent-, hex-) Based on McMurry, Organic Chemistry, Chapter 25, 6th 7 25.2 Depicting Carbohydrate Stereochemistry: Fischer Projections Carbohydrates have multiple chirality centers and common sets of atoms A chirality center C is projected into the plane of the paper and other groups are horizontal or vertical lines Groups forward from paper are always in horizontal line. The oxidized end of the molecule is always higher on the page (up) The projection can be seen with molecular models Based on McMurry, Organic Chemistry, Chapter 25, 6th 8 Stereochemical Reference The reference compounds are the two enantiomers of glyceraldehyde, C 3 H 6 O 3 A compound is D if the hydroxyl group at the chirality center farthest from the oxidized end of the sugar is on the right or L if it is on the left....
View Full Document

This document was uploaded on 01/03/2012.

Page1 / 64

Chapter25 - Chapter 25. Biomolecules: Carbohydrates Based...

This preview shows document pages 1 - 9. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online