CH4710 RM23

Cells are covered with a dense coating of ______ called ______. (Fill in the blank).

glycans, glycocalyx

in glucose all OH are ____.

equatorial

alpha and beta anomers

alpha: OH on the anomeric carbon is trans to carbon 6

beta: OH on the anomeric carbon is cis to carbon 6

Identify

D-glucose

Glc

Identify

N-Acetyl-D-glucosamine

GlcNAc

Identify

D-galactose

Gal

Identify

N-Acetyl-D-galactosamine

GalNAc

Identify

D-mannose

Man

Identify

D-xylose

Xyl

Identify

D-glucuronic acid

GlcA

Identify

L-Fucose

Fuc

Identify

N-Acetylneuraminic acid

NeuAc

carbohydrates

aldehydes or ketones with at least two OH groups

4 classes of carbohydrates

1. monosaccharides- simple sugar, one polyhydroxy unit

2. oligosaccharides- short chains of monosaccharide units

3. disaccharides- 2 monosaccharide units

4. polysaccharides- 10+ monosaccharide units

What joins monosaccharide units together to form chains?

glycosidic bonds

2 examples of polysaccharides

1. cellulose

2. glycogen

2 families of monosaccharides

1. aldoses

2. ketoses

aldose

structure in which the carbonyl group is at the end of the carbon chain (in the aldehyde group)

ketose

structure in which the carbonyl group is at any position besides the end of the carbon chain (in the ketone group)

trioses

simplest monosaccharides, three carbon backbone

tetroses

four carbon backbone

pentoses

five carbon backbone

How to draw Fischer Projection Formulas to represent 3D sugar structures

bonds drawn horizontally indicate bonds that project out of the paper

bonds drawn vertically indicate bonds that project into the paper

epimers

two sugars that differ only in the configuration around one carbon atom

True or false: In aqueous solutions, all monosaccharides with 5+ carbon backbone occur as cyclic structures

True as hell

anomers

isomeric forms of monosaccharides

(there are alpha anomers and beta anomers)

anomeric carbon

the carbonyl carbon atom

mutarotation

the interconversion of alpha and beta anomers

How to draw Haworth perspective formulas to represent 3D sugar structure

six membered ring is tilted to make its plane almost perpendicular to paper

bonds closest to reader are drawn thick

Are Fischer projections or Haworth perspectives more accurate?

Haworth perspectives

O-glycosidic bond

covalent linkage joining two monosaccharides

formed when an OH group of one sugar molecule reacts with the anomeric carbon of the other

reducing end

the end of a disaccharide/polysaccharide with a free anomeric carbon

Label the symbols

Fuc

Gal

Glc

Man

(Xyl is an orange star btw)

reducing end

the end of a disaccharide or polysaccharide chain with a free anomeric carbon

• when sugar monomers are joined together, the anomeric carbon (carbon 1) is usually used to bond with other monomers, so the reducing end is going to have carbon 1 free with no bond