Zusammenfassung der Ressource
Th1L07
Enzymes
- Main properties
- biological catalysts
- speed up the rate of the reaction
- reduces necessary free energy (delta
G) need to overcome the activation
energy
- do NOT alter final
equilibrium b/w reactants
and products
- proteins
- Dependent on many weak bonds e.g. hydrogen bonds, electrostatic
salt links and hydrophobic interactions
- Makes enzymes sensitive to changes
in their environment
- Inactive enzyme
- Denatured enzyme state
- e.g. by eating the protein, giving rise to a disorganised or tangled structure in which
the enzyme no longer has any catalytic activity
- temperature
- Between 20C, 30C and 40C for enzymes
found in the body, you will usually speed up
the reaction
- Up to 50C and beyond, denaturing of the protein will occur,
similarly going to far below 20C will also reduce reaction
velocity
- Enzyme catalysis
- Enzymes contain an active site
- substrate binds to the enzyme at the
active site producing an
enzyme-substrate complex
- enzyme is then disregarded at the final product
is revealed
- Stickase metaphor
- illustrates that enzymes should be complementary to the
substrates transition phase rather than the substrate itself to
bring about the activation of the reaction > product
- Substrate specificity
- catalyse only one type of reaction
and will act only on a few related
molecules ('Group...')
- few are so specific that they will
act only on a certain enzyme even
to the point will it will only act on
one stereoisomer
- presence of a groove or cleft of defined shape
called the active site into which only the
substrate of the correct shape and charge can
fit
- Relevance?
- multiple enzymes within the same cellular
compartment can co-exist without interfering with e/o
- allows for multiple metabolic pathways w/i cells
- Systematic classification scheme of 6
main classes
Anmerkungen:
- Six classes are divided into subgroups according to their substrate or source i.e. the type of reaction they catalyse
- Each enzyme IDed by individual 4 digit number
I.U.B. Commission on Enzymes - established the systematic classification on enzymes
Catalase 4 digit classification code - E.C. 1.11.1.6.
- mnemonic:
TO HILL
- transferase
- oxoreductase
- hydrolyase
- isomerase
- ligase
- lyases