Carbohydrates

Sugar structure 
MONOSACCHARIDE 
Glucose
Glucose (or Glucopyranose) is the most common sugars which has two different form, alpha and beta.

α-D-Glucose and β-D-Glucose

Galactose

Galactose is similar to Glucose, however, the fourth hydroxide on the ring projects upward

α-D-Galactose and β-D-Galactose

Fructose
A furanose ring structure with six carbons or (hexose)

α-D-Fructose and β-D-Fructose

Ribose

A furanose ring structure with five carbons or (pentose) 

α-D-Ribose and β-D-Ribose

N-acetylglucosamine (NAG)
It is a glucose with a "peptide-like" bond attaches on the second carbon

N-acetylglucosamine

β-D-Glucuronate 

β-D-Glucuronate

DISACCHARIDE 

Amylose (2 and more α-glucose)

It is a disaccharide which is created by α 1->4 glycosidic linkage.

The structure of amylose is a left handed helix, 6 glucoses/ turn, and -CH2OH groups project outward 

Two different projections of Amylose

Cellobiose  (2  β-glucose) 

It is created by β 1-> 4 glycosidic linkage. With more than 2 glucose, this chain will form Cellulose 

Chair Conformation of Cellobiose
Source: http://nl.wikipedia.org/wiki/Bestand:Cellobiose_skeletal.png

Cellobiose 

β-D-Lactose (β-Galactose and β-Glucose)
A sugar that found in milk, which is created by a β 1->4 glycosidic linkage 

Lactose molecules
Source: http://www.edinformatics.com/math_science/science_of_cooking/lactose.htm

Sucrose (α-Glucose and β-Fructose) 

Notice that the fructose molecule need to rotate to the left 180 degrees, around the z-axis (the axis that projects out of the plane). It is a non reducing sugar. 

Sucrose
Source: http://users.bergen.org/dondew/bio/AnP/Anp1/AnP1Tri1/CARB_ART/SUCROSE_SYNTH/SucroseSynth.html

Trehalose (α-Glucose and α-Glucose)

 It is animal blood sugar which is linked by α 1->1  glycosidic linkage 

Note: The right handed side glucose must rotate 180 degree to the left around the z-axis (the axis that projects out of the plane). 

Trehalose Haworth projection
Source: http://what-when-how.com/glycoconjugates-and-carbohydrates/polysaccharides-glycoconjugates-and-carbohydrates/

Source: Dr. Larry Jon Friesen' s Lectures