Carbohydrates

What is the empirical formula commonly associated with carbohydrates?

[CH2O]n.

What are the basic building blocks of carbohydrates?

Monosaccharides.

What does the term 'aldose' refer to in carbohydrates?

Monosaccharides with an aldehyde functional group.

What do we call monosaccharides that contain a ketone group?

Ketoses.

How many carbon atoms do tetroses have?

Four.

What is an enantiomer?

Isomers that are exact mirror images of each other.

What do the designators D- and L- refer to in carbohydrate chemistry?

They are used to denote the configuration of carbohydrate enantiomers.

What is a racemic mixture?

A mixture of equal amounts of two enantiomers.

What is the difference between configurations and conformations?

Configurations refer to the 3-dimensional arrangements of substituent groups, while conformations are different spatial arrangements resulting from free rotation about carbon-carbon single bonds.

What is an epimer?

Monosaccharides that differ in stereochemistry at only one chiral carbon.

How many isomers does a monosaccharide with N centers of asymmetry have?

2^N isomers.

What are the four D-isomers of aldopentoses?

They refer to the various configurations of aldopentoses, each differing at chiral centers.

What is mutarotation?

The process of interconversion of α- and β-anomers with the open chain form of a monosaccharide.

What is the outcome when an aldehyde group reacts with an alcohol group in the same molecule?

The formation of a hemiacetal.

What differentiates reducing sugars from non-reducing sugars?

Reducing sugars can undergo mutarotation and produce an aldehyde, while non-reducing sugars cannot.

What type of linkage connects monosaccharide units in disaccharides?

Glycosidic bonds.

What type of glycosidic bond is found in maltose?

An α-1,4-glycosidic bond.

What structural feature differentiates cellulose from glycogen?

Cellulose contains β-1,4 linkages, while glycogen contains α-1,4 and α-1,6 linkages.

What distinguishes amino sugars from regular sugars?

An amino group substitutes for one hydroxyl group.

Which sugars are components of RNA and DNA?

Ribose and deoxy-ribose.

Why are human blood types defined by carbohydrate structures?

Because A, B, and O antigens are carbohydrate structures found on cell surfaces.

What role do phosphorylated sugars play in cellular processes?

They function as intermediates in biochemical pathways.

What is the significance of not being able to have mutarotation in methylated sugars?

Methylated sugars lock the cyclic forms into either α- or β-anomer, preventing interconversion.