Biomolecules
Sugars
Sugars come in single units or ring structures called monomers. A single unit of sugar is called monosaccharide. 2 units would be a disaccharide and 3 or more would be a polysaccharide.
 
If the sugar has an aldehyde group in it is an "aldose" sugar. Note the addition of the suffix "ose". If it has a ketone group in it, it is called a "ketose". All monosaccharide sugars are reducing sugars. That means that they can be combined with oxygen and be reduced to simpler substances. Most disaccharides also reduce. The exception is sucrose, "table sugar" is a non-reducing sugar.
 
Sugars are normally ring structures. The ones below are drawn as split molecules.
 

         Fructose                         Mannose                      Arabinose                        Ribose                         Xylose
"fruit sugar" an aldo-
a 2-ketohexose hexose
 
Ribose sugar is found in RNA. Remove the oxygen from the 3rd C and you get Deoxyribose sugar found in DNA. Mannose and Xylose sugar is found in sugar-free gum. Sugar free gum is not really sugar free.  It is free of sugar that we can digest. These sugars do not get touched by any digestive process and hence simply pass through the gut. They provide sweetness because they are similar enough to sucrose to fool the taste buds but they have no nutritional value. The placement of the H and OH groups around the molecule dictate what the sugar is.
 
Glucose can be written in a linear form or as a ring structure.

 
Linear structures are good for showing monosaccharides but ring structures are better for showing disaccharides.
 
Disaccharides   C12H22O11
Maltose "malt sugar" 
                                                     glucose       +          glucose
 
Lactose "milk sugar" 
                                                   galactose      +       glucose
 
sucrose "table sugar" 
                                                     glucose        +        fructose
 
Polysaccharides are glucose monomers (C6H10O5)n
There are two main types. Cellulose and starch.
Cellulose

The C-O-C bond between each monomer is orientated in a special way. We, as humans do not have the enzyme to break these bonds. If we did we could digest wood and paper. Termites have in their guts a bacteria which does have this enzyme. Therefore the termite eats the wood. The bacteria digests it. The bacteria get a home and the termite get digested sugar monomers. A symbiotic relationship.
 
Starch

Starch is a polysaccharide that we do have the enzyme for. Starch gets digested into individual glucose monomers.  Note the different C-O-C bond pattern between the cellulose and starch.
 
Amino Acids
The basic structure of the amino acids is that of an amino group along with a carboxylic acid group around a single C.

Three of the four bonds around the carbon are taken up with the amino group, the acid and the H. The fourth C covalent bond can be one of 20 different things and is represented by the R group.
 
Below are the 20 common amino acids. The chart is organized as to size, polarity, alkly and aromatic.
Nonaromatic  Aromatic 
Nonpolar
Alanine 
(ala)
Valine
(val)
Leucine
(leu)
Isoleucine 
(ile)
Phenylalanine (phe) Tryptophan
(trp)
                    Smaller <-------------------------------------------------------------------------------------------------------------> Bulkier
Polar uncharged Glycine 
(gly)
Serine
(ser)
Theonine 
(thr)
Asparagine 
(asn)
Glutamine 
(gln)
Tyrosine
(tyr)

                   Less polar <-----------------------------------------------------------------------------------------------------> More polar
Ionizable Glutamic acid (glu) Aspartic acid (asp) Histidine 
(his)
Lysine 
(lys)
Arginine 
(arg)


                         Acidic <----------------------------------------------------------------------------------------------> Basic
Special Structural Property

Proline 
(pro)
Methionine 
(met)
Cysteine 
(cys)




Amino acids are held together in long polypeptide chains.

  ----------->     + H2O
                                                                                                  a dipeptide
                                                             notice the CONH2 amide bond formed between the two amino acids.