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Ch. 4: Carbohydrate Structure and Function

Terms in this set (67)

The most basic form of a monosaccharide is called a?
Triose
A carbohydrate with 4 carbons is known as a?
Tetrose
Carbohydrates containing an aldehyde group as their most oxidized functional group are called?
Aldoses
In a ketose, what is the most oxidized functional group?
ketone
A 6 carbon sugar with an aldehyde group is called?
Aldohexose
The most basic monosaccharide is called?
Glyceraldehyde
Sugars with the highest-numbered chiral carbon with the -OH group on the left are?
L-sugars
A pair of nonsuperimposable molecules that differ at at least one-but not all-chiral carbons are?
Diastereomers
A subtype of diastereomers that differ at exactly one chiral carbon are called?
Epimers
A subtype of epimers that differ at the anomeric carbon are called?
Anomers
What is the basis for building complex carbs and requires the anomeric carbon to link to another sugar?
Glycoside formation
What is the main structural component for plant cell walls nd is a main source of fiber in the human diet?
Cellulose
Amylose and amylopectin are both examples of?
Starches
What functions as a main energy storage form for animals?
Glycogen
Glucose-alpha-1,2-fructose is?
Sucrose
Galactose-beta-1,4-glucose is?
lactose
glucose-alpha-1,4-glucose is?
maltose
The simplest aldose is called?
glyceraldehyde
In an aldose, the carbonyl carbon will always be given which number?
1
The simplest ketose is called?
dihydroxyaceton
In a ketose, the loswest number that the carbonyl carbon can be assigned is?
2
2 sugars that are in the same family (meaning both are either ketoses or aldoses), that are not identical and are not mirror images of each other are called?
diastereomers
Because monosaccharides contain both a hydroxyl group (which can serve as a nucleophile), and a carbonyl group (that can serve as an electrophile), they can undergo intramolecular rxns to form?
hemiacetals/ketals
Because of ring strain, the only cyclic molecules that are stable in solution are?
pyranose (6) and furanose (5) ringss
After a carb goes from straight to chain formation, the carbonyl carbon becomes chiral and is now referred to as?
anomeric carbon
alpha and beta ring forms of the same sugar are examples of?
anomers
In an alpha anomer, the hydroxyl group of c-1 is positioned ______ to the CH2OH substituent?
trans
In beta anomer, the hydroxyl group of c-1 is positioned ______ to the CH2OH substituent?
cis
_________ _______ depict cyclic sugars as planar 5 or 6 membered rings w/ the top and bottom faces of the ring nearly perpendicular to the page
haworth projections
In reality, furanose rings are very close to taking on a _______ configuration?
planar
Pyranose rings adobt a _______ configuration?
chair
When we convert the monosaccharide from its straight -chain fischer projection to Haworth, any group on the right in the fischer projection will point ____?
down
Exposing hemicacetal rings to water will result in a phenomenon known as?
mutarotation
Mutarotation occurs quicker when the rxn is exposed to?
acid
The alpha anomeric configuration is less favored because of?
sterics. Alpha conformation is trans
Oxidation of carbs in the human body results in?
energy production
As monosaccharides switch b/w anomeric configurations, the hemiacetal rings spend a short period of time in the open-chain aldehyde form allowing the aldehyde to be oxidized, thus producing an?
aldonic acid
Any monosaccharide containing a hemiacetal ring is referred to as a?
reducing sugar
Oxidation of an aldose that is in closed ring form results in a?
lactone
A cyclic ester with a carbonyl group persisting on the anomeric carbon is termed a?
lactone
Which reagent utilizes Ag(NH3)2+ as an oxidizing agent to detect the presence of a reducing sugar?
Tollen's reagent
In a positive Tollen's test, an aldehyde with reduce the reagent to?
metallic silver
In a positive benedicts reagent test, what can you expect to see?
red precipitate
Which reducing sugar-detecting reagent involves Cu2O?
Benedict's reagent
Glucose oxidase is an enzyme used to test for the presence of?
glucose
In order for a ketone within a hemiketal to be oxidized, what process must occur?
tautomerization
The rearrangement of bonds in a compound, usually by moving a hydrogen and forming a double bond is known as?
tautomerization
Tautomerization of a hemiketal in basic conditions results in the production of?
enol
After the aldehyde group of an aldose is reduced to an alcohol, the compound is considered an?
alditol
When a hydrogen replaces a hydroxyl group on a sugar, this sugar now becomes a?
deoxy sugar
Because carbohydrates contain hydroxyl groups, they are able to participate in rxns with COOHs and COOH derivatives to form ?
Esters
Hemiacetals react with alcohols to form?
acetals
acetals are also known as?
glycosides
What is the by-product of glycoside formation?
Water
During glycoside formation, the anomeric hydroxyl group on a sugar is transformed into ?
alkoxy group
Disaccharides and Polysaccharides form as a result of what type of bonds between monosaccharides?
glycosidic
Glycosides derived from furanose rings are referred to as?
furanosides
A polysaccharide composed entirely of glucose (or any other monosaccharide) is called?
homopolysaccharide
A polymer made up of more than one type of monosaccharide is considered a?
heteropolysaccharide
Why is cellulose a good source of fiber for humans?
Beta linkages are undigestable
What do the 3 most important biological polysaccharides all have in common?
All composed of D-glucose
When an internal monosaccharide in a polymer chain forms more than 2 glycosidic bonds, this is called?
branching
Alpha 1,4 glycosidic bonds are associated with which structural polymer?
amylose
Alpha 1,6 glycosidic bonds in the form of branches is associated with which starch polymer?
amylopectin
A well known reagent that tests for the presence of starch is?
Iodine
In order to degrade amylose into strictly maltose fragments, one must use which enzyme?
beta-amylase
Which structural polymer is known for being HIGHLY branched, thus increasing its solubility?
glycogen
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