Into to Carbs Flashcards
carbohydrate formula
CnH2O
role of carbohydrate
store energy
make up part of DNA/RNA
bacteria cell wall and ECM
Sometime links to proteins andd lipids as glyconjugates
what makes up maltose
2 glucose : (Glc-a(1,4)-Glc)
what makes up lactose
glucose and galactose (Gal-b(1,4)-Glc)
what makes up sucrose
glucose and fructose (Glc-a(1,2)-Fru)
oligosaccharides vs polsccharides
3-20 subunits vs 100s
chiral carbon
GLYCERALDEHYDE
Therefore, exists in two enantiomeric forms: D (dextrorotary) and L (levorotary)
Non-superimposable mirror images
Rotate plane-polarized light in opposite directions
What is an stereoisomer
atoms are connected in same order with different spatial arrangement
constitutional isomers
different order of attachment
GLYCERALDEHYDE VS DIHYDROXYACETONE
Epimers ?
type of diastereomers that differ at 1 carbon
D galactose and D glucose
also ribose and deoxyribose
anomers ?
alpha delta glucose and b delta glucose
different hemi/acetal carbonn in cyclic structure
diasteroisomer
not mirror images
D- ALTROSE AND D-GLUCOSE
ENANTIOMERS
mirror image
D Glycrtaldehyde and L-glyceraldehyde
In anomers cyclization involves intramolecular nucleophilic attack on
penultimate OH on carbonyl (C1) carbon
type of hemiactal anomer vs hemiketal anomer
hemiacteal : alpha delta glucopyranose and beta delta glucopyranose
hemi keta; is alpha/beta delta fructofuranose
reducing sugar
All have, or can form, a free aldehyde group
reducing sugar examples
glucose, galactose, mannose, fructose, maltose, lactose
why isn’t sucrose a reducing sugar
Because its C2 carbon is “tied up” in forming an acetal linkage
why is fructose a reducing sugar
because a “keto-enol tautomerization” allows formation of aldehyde from ketone
lactose intolerant ?
deficency in the expressionof the gebe for the enzyme lactase which breaks down lactose
types of Starch?
amylose and amylopectin
amylose ?
Linear polymer of glucose
Essentially “polymaltose”
Only a(1,4) linkages
Amylopectin?
Branched every 30 residues Contains a(1,6) branch points as well as a(1,4) linkages
glycogen ?
storage form of glucose in animals in the liver and muscle
cellulose
b(1,4) linkages
Alternating residues are “flipped”;
High tensile strength: found in woody stems of plants, blades of grass
Hydrolyzed by the enzyme cellulase
cellulase
humans lack
humans cant breakdown cellulose
glycosaminosglycans?
Found in the ECM in proteoglycans
Complex of carbohydrate and protein
Very large
role of glycosaminosglycans?
Roles: cushioning, lubrication, adhesion
secreted proteins in glycosylation?
EPO, LSH, TSH
glycoconjugates
glycoproteins
proteoglycans
glycolipids
proteoglcyan
a glycoconjugate that are made up of proteins and GAGs
example of a proteoglycan?
aggrecan-component of cartilage, acts as shock absorber
the globular domain of aggrecan
involved in hyaluronan binding,
cell adhesion
chondrocyte apoptosis
