CHAPTER 2. ORGANICMACROMOLECULES 2.6
More practice video solutions or help at http://www.everythingscience.co.za(1.) 01pi (2.) 01pj (3.) 01pkNucleic Acids ESCAP
You will remember thatwe mentioned earlier that each protein is different because of
its unique sequence ofamino acids. But whatcontrols how the aminoacids arrange
themselves to form thespecific proteins that areneeded by an organism? This task is
for the gene. A gene contains DNA(deoxyribonucleic acid)which is a polymer that
belongs to a class of compounds called the nucleic acids. DNA is the genetic material
that organisms inherit from their parents. It is DNA that provides the genetic coding
that is needed to form the specific proteins that an organism needs. Another nucleic
acid is RNA (ribonucleicacid). The diagram in figure 2.14 shows an RNAmolecule.
The DNA polymer is made up of monomers called nucleotides. Each nucleotide has
three parts: a sugar, a phosphate and a nitrogenous base. DNA is a double-stranded
helix (a helix is basicallya coil). Or you can think of it as two RNA molecules bonded
together.