07 - CHAPTER 7 Carbohydrates Biochemistry The Molecular...

Info icon This preview shows pages 1–8. Sign up to view the full content.

View Full Document Right Arrow Icon
Biochemistry: The Molecular Basis of Life, 4/e McKee/McKee Copyright © 2009 by Oxford University Press, Inc. C H A P T E R 7 Carbohydrates
Image of page 1

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

View Full Document Right Arrow Icon
Overview Carbohydrate = [CH 2 O] n Most abundant organic molecule class – photosynthesis. Functions: - energy http://www.youtube.com/watch?v=jJvAL-iiLnQ&feature=related - structural elements - precursors - cell-cell communication - cell identity - information system (sugar code) - glycoconjugates Mono-, di-, oligo- & poly- Monosaccharides (simple sugars) = polyhydroxy aldehydes (aldoses) or ketones (ketoses). Triose, tetrose, pentose, hexose , heptose, ... The smallest sugars: glyceraldehyde & dihydroxyacetone . Fischer projection: vertical C-backbone; most oxidized C at the top. 7.1 Monosaccharides FIGURE 7.2 Glyceraldehyde (an Aldotriose) and Dihydroxyacetone (a Ketotriose)
Image of page 2
Monosaccharide stereoisomers Multiple chiral C atoms; n chiral atoms ! 2 n stereoisomers. D- (most natural sugars) & L- stereoisomers – based on the C that is most remote from C=O. D- is based on D-glyceraldehyde. Diastereomers = stereoisomers that are not enantiomers. Epimers = diastereomers that differ by 1 assymetrical C. FIGURE 7.3 The D- Family of Aldoses FIGURE 7.4 The Optical Isomers D- and L-Ribose and D- and L-Arabinose
Image of page 3

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

View Full Document Right Arrow Icon
FIGURE 7.5 Formation of Hemiacetals and Hemiketals Cyclic structure of monosaccharides Cyclic form (hemiacetal or hemiketal) most stable. Cyclization ! new chiral C (anomeric): 2 anomers. For D sugars: α -anomer : ‘new’ OH - down β -anomer: ‘new’ OH - up. Haworth structures Pentose = furanose, hexose = pyranose. FIGURE 7.6 Monosaccharide Structure FIGURE 7.7 Haworth Structures of the Anomers of D-Glucose FIGURE 7.8 Furan and Pyran
Image of page 4
Conformational structures Most realistic. FIGURE 7.9 Fischer and Haworth Representations of D-Fructose FIGURE 7.10 α - and β -D-Glucose
Image of page 5

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

View Full Document Right Arrow Icon
FIGURE 7.11 Equilibrium Mixture of D-Glucose Mutarotation = spontaneous interconversion of α & β forms in water.
Image of page 6
FIGURE 7.12
Image of page 7

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

View Full Document Right Arrow Icon
Image of page 8
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

What students are saying

  • Left Quote Icon

    As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

    Student Picture

    Kiran Temple University Fox School of Business ‘17, Course Hero Intern

  • Left Quote Icon

    I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

    Student Picture

    Dana University of Pennsylvania ‘17, Course Hero Intern

  • Left Quote Icon

    The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

    Student Picture

    Jill Tulane University ‘16, Course Hero Intern