Abunch of amino acids attach together is called a

A polypeptide is a single linear chain of many amino acids, held together by amide bonds. A protein consists of one or more polypeptides (more than about 50 amino acids long). An oligopeptide consists of only a few amino acids (between two and twenty).  

A polypeptide

the sugar-phosphate backbone forms the structural framework of nucleic acids, including dna and rna. this backbone is composed of alternating sugar and phosphate groups, and defines directionality of the molecule.

geologic time scale (for gradpoint) =)