Binds to the DNA strand at a specific sequence of the gene called a promoter; Unwinds and unlinks the two strands of DNA; Uses one of the DNA strands as a guide or template; Matches new nucleotides with their complements on the DNA strand (G with C, A with U -- remember that RNA has uracil (U) instead of thymine (T))
Carbohydrates contain three major categories of molecules: monosaccharides (or simple sugars), disaccharides, and polysaccharides. 1. Monosaccharides: This group, also known as simple sugars, is the simplest carbohydrate form.
For example, grape sugar is the monosaccharide glucose, cane sugar is the disaccharide sucrose and milk sugar is the disaccharide lactose (see illustration). Carbohydrates perform numerous roles in living organisms.ollowing this definition, some chemists considered formaldehyde (CH 2 O) to be the simplest carbohydrate, while others claimed that title for glycolaldehyde. Today the term is generally understood in the biochemistry sense, which excludes compounds with only one or two carbons.