Polysaccharides are long chains of monosaccharides made of carbon hydrogen and oxygen often in a 1:2:1 ratio. Polypeptides are long chains of amino acids made of carbon hydrogen oxygen nitrogen and a variety of other element not in a particular ratio.
Polysaccharides include starch and glycogen and are often used for energy storage in organisms. Below is the structure of part of a starch molecule (the full molecule is too large to show because it can be hundreds of monomers long):
Polypeptides are long unbranched chains of amino acids and can link together to form proteins like hemoglobin. Below is an image explaining a bit about protein structure:
