Chapter 8 - Carbohydrates bond Flashcards
Maltose
basis of starch
alpha 1-4 glucose linkage
glucose - alpha - 1,4 - glucose
Cellubiose
basis of cellulose
beta 1-4 glucose linkage
Beta - 1,4- glucose
Sucrose
alpha-D-glucose + beta-D-Fructose (1-2 linkage)
Glychosidic bond formation with molecules other than sugars..
nucleosides
N-glycosides
-OH reacts with amine thru a condensation rxn
compound family derived from modified galactose
found in glycolipids
Glycoproteins and glycolipids
lipid or protein linked oligosaccharides
typically located on cell surface with varied functions -> “glycocalyx”
varying monomers, derivatives, and linkages
varied shapes from branching and number of monomers
ex. microvilli
Glycocalyx
carbohydrates and protein
highly cross-linked - strengthens PM and contributes to cell-cell recognition
Structure supports function - classified by biological role
for polysaccharides
starch, cellulose, glycogen, chitin
near anhydrous storage (less weight) and smaller space for packing (starch); insoluble in water but can be hydrated (helical for anhydrous storage; many ends for rapid degradation)
intra-and interstrand hbonding for strength (cellulose) (extended structure to align hydrogen bonding groups; sheet formation)
branding for more “ends” -> easy and rapid breakdown (glycogen)
Overlapping features of cellulose plus cross-linking capabilities (chitin)
Examples of homopolysaccharides and their linkage
Starch (1-4 alpha glucose linkage)
Glycogen
Glucose (1-4 beta glucose linkage)
Starch
“anydrous” glucose storage in plant cells (2 components)
10-30% alpha-amylose (linear) and 70-90% aylopectin (branched) -> depends on source (branched gives quick energy storage)
varied length about 10^6 residues
(helical for anhydrous storage; many ends for rapid degradation)
Glycogen
Animal “starch”
similar to branched starch component
Cellulose
plant structural polymer
linkage and shape results in high tensile strenth and flexibiliy
isomer of amylose starch component
Amylose
a linear polycglucose joined by alpha 1-4 bonds
linear and left-handed helical
left-handed b/c adjacent glucose residues twist relative to each other
forms double-helix structure with water inside and out of amylose helix
single reducing and non-reducing end
Amylopectin
a branched polyglucose built from alpha 1-4 and 1-6 bonds
branched about every 25-30 residues (alpha 1-6) linkage
single reducing end except for branches
Lactose
B-Galactose + B-Glucose (1-4 linkage)
Blood Glucose Test
Enzyme (glucose oxidase) very specific to D-glucose.
Catalyzes beta-D-glucose to D-gluconic acid (oxidizes C1)
The oxygen is in the presence of water and is converted to H2O2
H2O2 is reacted with Peroxidase enzyme to produce color. More intense color = more glucose
Too uch insulin presnet - glucose levels too low and vice versa
