Biomolecules and Enzymes

Isoenzymes (or isozymes) are different forms of an enzyme that catalyze the same reaction but have different amino acid sequences. These structural differences can arise from different genes or post-translational modifications, allowing the enzyme to function optimally in different tissues or under different conditions.

Interferons are signaling proteins produced by host cells in response to viral infections. They form part of the innate immune system's defense against viruses by interfering with viral replication.

Chaperones are a functionally related group of proteins assisting proper protein folding in the cell under physiological and stress conditions. Prions are proteins that are unique in their ability to reproduce on their own and become infectious.

Glycerate 3-phosphate acts as a precursor for serine which in turn, can act as precursor to create cysteine and glycine through the homocysteine cycle.

Milk paint is a non-toxic water based mixture used as a paint. It is made from milk and lime with or without pigments added for colour. Borax is added in addition to lime in the milk paint recipe to assist the lime in dissolving casein and as a preservative.

EC 6.3 includes ligases used to form carbon-nitrogen bonds.

Peptidoglycan consists of sugar derivatives (N-acetylglucosamine and N-acetylmuramic acid) cross-linked by short peptide chains of amino acids. This mesh-like structure provides strength to bacterial cell walls.

Histidine has an imidazole ring which often sits inside the active site of an enzyme and helps bonds to be broken or made. It can do this because it can exist in two states -uncharged, or positively charged.

Isoleucine is similar to leucine and valine except that the orientation of the atoms in the sidechain is slightly different. Isoleucine also has two centres of asymmetry.It is an aliphatic amino acid.

Glutathione is a tripeptide that contains an unusual peptide linkage between the amine group of cysteine and the carboxyl group of the glutamate side-chain. It is an antioxidant, preventing damage to important cellular components caused by reactive oxygen species such as free radicals and peroxides.

Lysine, is an essential amino acid. Lysine is important for proper growth, and it plays an essential role in the production of carnitine, a nutrient responsible for converting fatty acids into energy and helping to lower cholesterol. It is a basic amino acid.

Glutamic acid is one of the 20 proteinogenic amino acids, and its codons are GAA and GAG. It is a non-essential amino acid. The carboxylate anions and salts of glutamic acid are known as glutamates.

Glycine is the simplest and smallest of all amino acids, and the only one which is not optically active since it has a single hydrogen atom as it's sidechain.

Methionine is a very special amino acid in that it is the start amino acid in the process of translation (protein synthesis. Methionine has a highly hydrophobic sidechain.

Ligands are those provided by nature, especially including the side chains of amino acids, and many cofactors such as porphyrins. For example: hemoglobin