Chapter 8 Flashcards
What is the general formula for carbohydrates?
(CH2O)n
What is a monosaccharide?
Simple sugar (one residue)
What is an oligosaccharide?
2-10 simple sugar residues
What is a polysaccharide?
Polymer of simple sugars
What is an aldose?
monosaccharide with a carbonyl group on the endmost Carbon
What is a ketose?
monosaccharide with a ketose group on the endmost carbon (COCH2OH)
How many carbons are needed for each monosaccharide to be considered chiral?
Aldose: 3C or more
Ketose: 4C or more
What carbon is stereochemistry of a monosaccharide determined with?
Highest numbered or lowest chiral carbon – one closest to CH2OH group
What are the two sterochemistry designations of monosaccharides?
D (OH is on the right)
L (OH is on the left)
What sterochemical designation of sugars predominates in nature?
D sugars
What is a stereoisomer?
Compounds that only differ in spatial arrangement of atoms – same chemical formula
What is an enantiomer?
Nonsuperimposeable mirror images (D vs L)
What is a diastereomer?
Stereoisomers (same chemical formula, different arrangement) that aren’t mirror images
What is an epimer?
Diastereomer (different arrangements of same chemical formula that aren’t mirror images) that only differ at a single stereocenter
What is the difference between a hemiacetal and hemiketal?
Hemiacetal - H
Hemiketal - R group
How do you form a hemiacetal? Hemiketal?
Alcohol + Aldehyde = Hemiacetal
Alcohol + Ketone = Hemiketal
What is a reducing sugar?
Sugar with a free aldehyde group
What is the function of acetals and ketals in sugars?
Links multiple monosaccharides together (two R group connections)
What is the reaction that forms glycosidic bonds?
Condensation Reaction
What type of glycosidic bond is hard for the body to break?
Beta
What is the difference between homopolysaccharides and heteropolysaccharides?
Homopolysaccharides consist of repeating single sugar
Heteropolysaccharide consist of multiple sugars