Tag Archives: nucleic acids

Week 3: Structure and function of nucleic acids and proteins

Image result for transcription and translation diagram

Learning Intention: To understand nucleic acids as information molecules that encode instructions for the synthesis of proteins in cells and the processes of transcription and translation in cells. Students will also understand protein functional diversity and the nature of the proteome as well as the functional importance of the four hierarchal levels of protein structure. They will perform experiments that demonstrate the effect of temperature and pH on enzymes.

  • Catalase is an enzyme found in liver extract that breaks down hydrogen peroxide (H2O2) into water and oxygen.
  • Hydrogen peroxide is a toxic product of digestion that needs to be eliminated from the body. Water and oxygen are the safe products of hydrogen peroxide breakdown.
  • Primary structure of protein – order of amino acids
  • Secondary structure – alpha helix, beta pleated sheets or random coils
  • Tertiary structure – folding of the polypeptide chain due to disulphide bridges and other attractions or repulsions between molecules.
  • Quarternary structure – two or more polypeptide chains folded together to form a complex protein.

Biological macromolecules: Nucleic acids

Biomacromolecules – Nucleic acids and proteins (Part A) from GTAC

Biomolecules – Nucleic acids and proteins (Part B) from GTAC

Nucleic acids (DNA and RNA) are the next group of macromolecules that we are looking at. Nucleic acids are made up of monomer units that consist of a phosphate group, a sugar unit and a nitrogenous base. The nitrogenous bases in DNA are Thymine (T), Adenine (A), Guanine(G) and Cytosine (C). In RNA, the Thymine (T) is replaced by Uracil (U). Thymine (or Uracil in RNA) always pairs with Adenine (2 hydrogen bonds) and Guanine always pairs with Cytosine (3 hydrogen bonds).