Text Book enzymes Flashcards
Catalyst
they reduce the activation energy of a chemical reaction and increase the rate without being used up themselves remaining unchanged
Turnover number
the number of substrate molecules converted per second
What breaks down glycosidic bonds/ester bonds
Glycosidase
esterase’s
What can a non-functioning enzyme cause
may lead to serious disease as it may mean that a metabolic reaction cannot proceed properly
Why is the daily amount of nicotinamide so low
1) The NAD is recycled/regenerated after it has been changed during an enzyme-catalysed reaction in which it is used as a coenzyme.
What bond does a co-enzyme form
ionic
How do enzymes lower the activation energy
bring the substrate molecules close together, as the substrate molecules fit into the enzyme’s active site, and form S–E complexes, and stay there long enough to reac
How can there be multiple reactions taking place at the same time in a cell
substrates are catalysed by a specific enzymes meaning that there an be many different enzymes within the cell at once
-Many reactions take place in different organelles and so are separate from each other
Disulphide bridges
Are heat stable
Why can an enzyme still catalyse a reaction after it has been cooled but not when it has been heated
Cooling the enzyme slows the rate of reaction but does not permanently alter the molecular structure. So, on warming to 40°C, enzyme molecules gain KE and can move again – they catalyse the reaction. Enzymes that have been boiled are denatured and this involves irreversible change to the shape of the active site
Independent variable
this is the variable that the investigator changes to find out how the DV is affected.
Dependant variable
varies as a result of changing the IV
pH
changes the balance of H ions/protons which can alter the shape of the enzymes active site if this interferes then the active site of the enzyme can be altered and no longer complimentary to the substrate so an ESC can no longer be formed
-make bonds outside its tertiary structure
Why do fungi/bacteria have the enzyme urease
to breakdown urea that is in the soil (derived from nitrogenous waste/urine) to ammonia that can be absorbed and used to make new amino acids, for protein synthesis.
Controlled in an enzyme reaction and why
If temperature changes, the enzyme and substrate molecules will have more or less KE and this will alter rate of collision/rate of formation of ES complexes/formation of product molecules.
(b) If time alters, there will be more/less time for ES complexes to form, so more/less product will form.
(c) If reactant molecules are well mixed, this increases the chance of collisions/formation of ES complexes, so will increase rate of reaction.
(d) Wavelength affects absorption and this is what is being used to measure rate of reaction
