Genetic engineering involves changing the DNA of an organism, usually by deleting, inserting or editing a gene to produce desired characteristics.
The final 3D structure of a protein. This structure is produced when the secondary structure of the polypeptide chain is folded.
An intermolecular attractive force between hydrogen, when it is covalently bonded to a highly electronegative atom (fluorine, oxygen or nitrogen), and an oxygen, nitrogen or fluorine atom on another molecule.
Specific in three dimensions.
The use of biological organisms or enzymes to create, break down or transform a material.
A protein digesting enzyme found in the mammalian small intestine that is activated by trypsin.
Process where microorganisms are cultured so that they reproduce and increase in quantity.
Bonds formed by the complete transfer of one or more electron from one atom to another, so both achieve a stable outer shell. The positive and negative ions formed are held together by strong electrostatic forces - these are ionic bonds.
A protein-digesting enzyme found in the mammalian small intestine.
A protein-digesting enzyme found in the mammalian stomach.
The enzyme that catalyses the breakdown of urea and the first pure enzyme to be extracted and crystallised.
A complex carbohydrate made as an energy store plants
The waste material left at the end of the digestive process made up of undigested food, dead cells, bacteria and water
The poisonous waste compound produced when excess amino acids are broken down in your liver
A common term for the digestive system.
1. Enzymes are proteins: Most enzymes are globular proteins. The bonds holding the amino acids together are peptide bonds but hydrogen bonds, disulfide bonds and ionic bonds work together to produce a secondary and tertiary structure.
Most enzymes are globular proteins
2. Enzymes have an active site: Within the globular protein structure of an enzyme is the active site. This is a 3D depression or hollow shape that is vital to the way the enzyme functions. The three dimensional, stereospecific shape of the active site is the result of the folding of the protein molecule. Anything that affects the shape of the active site will affect the ability of the enzyme to bind to the substrate or substrates and catalyse a reaction.
This computer generated model of the enzyme COX-2 shows the active site in red (Jeff Dahl, public domain).
3. Enzymes are very specific: An enzyme will only catalyse one type of reaction. Some enzymes are so specific that they will only catalyse one particular reaction. This is due to shape of the active site. The active site is stereospecific – in other words, it is specific in three dimensions. So, for example, it will only bind to one stereoisomer or enantiomer of a substrate molecule, not both (See Chemistry of Life, page 4).
4. Enzymes change the rate of a reaction: They act as catalysts so they do not affect the end products or the equilibrium of the reaction that they catalyse.