How are enzymes classified? Flashcards
How are enzymes named
Take the substrate and add the suffix “ase”
Prote ase
Amyl ase
Lip ase
What are 2 other examples of older names which give no clue to the substrate they catalyse
- Trypsin
- Pepson
How might enzymes be classified
- According to the type of reaction they catalyse
- e.g. Alcohol dehydrogenase removes hydrogen from alcohol
- Another example is
- DNA polymerase catlyses the formation and break down of DNA by polymerisations
What are the 6 mains groups of enzymes classified by the nature of their actions
- Hydrolases
- Oxoreductases
- Oxidases
- Transferases
- Isomerases
- Lyases
- Ligases
What is the function of the hydrolase group of enzymes?
- Catalyses the hydrolysis of a substrate by adding a molecule of water
What is an example of a hydrolase
- DIgestive enzymes which work in our gut and can also be found in germinating seeds
What is an example of a hydrolase catlytic reaction
- Maltone → maltase glucose + glucose
- Lipid → Lipase fatty acids + glycerol
What is the function of oxyreductase
- Oxoreductases are involved in oxidation and reduction reactions
- i.e. Also known as redox reactions
What are two types of oxyreductases
- Dehydrogenases
- Oxidases
What is the function of dehydrogenases
- Dehydrogenases oxidase the substrate by removing hydrogen, passing it on to a hydrogen acceptor or co factor
What is the function of oxidases
- Catlyse the addition of oxygen to hydrogen forming water
What is the function of transferases
They transfer a group of atoms from one molecule to another
What are two types of transferases
- Transaminases
- Transfer amino acids (NH2) from one atom to another, enabling organisms to make certain types of amino acids
- Phosphotranferases
- Control the transfer of phosphate groups in respiration
What is the function of isomerases
- Isomerases control the coversion of one isomer to another by transfering a group of atoms from one molecule to another
What is the function of Lyases
- Lyases break chemical bonds within the addition of water (hydrolysis)
What is an example of a lyase
- Decarboxylase is a Lyase which removes carboxyl groups from the respiratory substrates to release carbon dioxide
What is the function of ligases
- Ligases catluse reactions in which new chemical bonds are formed using ATP as a source of energy
- e.g. DNA ligase is involved in the synthesis of DNA
