---

Dextrorotatory amino acids rotate the polarized light towards right e.g. All non proteinous amino acids.

---

Oligosaccharides	Disaccharides
(1) Contain 2 to 10 units of monosaccharides. (2) Slightly soluble in water. (3) Tastelss. (4) Form glycoalyx on plasma membrane.	(1) Contain 2 units of monosaccharides. (2) Soluble in water. (3) Sweet. (4) Form storage sugars.

---

Co-enzymes are organic compounds which are bound to the enzymes to make them catalytically active. They bind to the enzyme transiently at the time of catalysis and help in the reaction. They also act as co-factors in a number of enzyme catalysed reactions. For examples. Nicotinamide adenine dinucleotide (NAD), Nicotinamide adenine dinucleotide phosphate (NADP), Flavin mononucleotide (FMN), Flavin adeine dinucleotide (FAD) and co-enzyme A (CoA) are important co-enzymes.

 

---

Laevorotatory amino acids rotate the polarized light towards left. 

---

Metal ions help in enzyme action by forming coordination bond with the side chains of the active site of the enzyme and one or two coordination bond with the substrate thus increasing the catalytic activity of the enzymes. For example zinc acts as an co-factor for the enzyme carboxy peptidases.Copper is a component of several enzymes .