Biochemistry Chapter 4: Carbohydrate Structure and Function Flashcards
What are 3 carbon sugars called?
trioses
What are 4 carbon sugars called tetroses?
tetroses
What are sugars with aldehydes as their most oxidized group?
aldoses
What are sugars with ketones as their most oxidized group?
ketoses
How can you tell if glucose is in D- or L- form?
Sugars with the highest numbered chiral carbon with the OH on the right are D-
—- OH on the left are L- forms
What are diastereomers?
nonsuperimposable configurations of molecules with similar connectivity. Differ at at least 1, but not all-chiral carbons
What are epimers?
subtype of diastereomer that differ at exactly one chiral carbon
What are anomers?
subtype of epimer that differ at the anomeric carbon
What is the anomeric carbon?
New chiral center formed in ring closure; it was the carbon containing the carbonyl in the straight-chain form.
What are alpha-anomers?
Have the OH on the anomeric carbon trans to the free CH2OH group
What are the beta-anomers?
-OH on the anomeric carbon is cis to the free CH2OH group
What are hawthorne projections?
Represent 3D structure.
What is mutarotation?
When cyclic compounds shift from one anomeric form to another with the straight-chain form as an intermediate.
What types of reactions can monosaccharides undergo?
oxidation-reduction, esterification and glycoside formation
What can aldoses be oxidized and reduced to?
Ox: aldonic acids
Red: Alditols
Sugars that can be oxidized are _____.
Reducing sugars
How can reducing sugars be detected?
Tollen’s or Benedict’s reagents
What are deoxy sugars?
sugars with a -H group replacing an -OH group
What is formed when sugars react with carboxylic acids?
esterification
What is phosphorylation?
phosphate ester is formed by transferring a phosphate group from ATP onto a sugar
What is glycoside formation?
basis for building complex carbohydrates and requires the anomeric carbon to link to another sugar
What are the three common disaccharides?
sucrose, lactose, maltose
What are three types of polysaccharides?
cellulose, starch and glycogen
Why can we not digest cellulose?
humans cannot digest beta linkages
What is tautomerization?
rearrangement of bonds in a compound, usually by moving a hydrogen and forming a double bond.
What is esterfication?
carbohydrates react with carboxylic acids to form esters
What linkages does cellulose have?
beta 1,4 linkages
What linkages does starch have?
amylose - alpha 1,4 linkages
amylopectin - alpha 1,4 and alpha 1,6
What linkages does glycogen have?
alpha 1,6 and alpha 1,4
