Enzymes Flashcards
what type of protein are enzymes
globular
how do enzymes increase the rate of a reaction?
lowers the activation energy, by e.g bringing reactants together to react
True or False unwanted products are produced by enzymes
false
How can cells regulate how quickly enzymes catalyze a reaction
increase/decrease the number of enzymes catalyzing the reaction = faster/slower reaction
define an enzyme
biological catalysts (1) that speed up the rate of reaction (2)in living organisms (3)
turnover number meaning
no. of reactions an enzyme can catalyse per second
The greater the activation energy needed the …. rate of of reaction. FIll in the blank
slower
What 2 things are needed for a reaction with an enzyme to occur
- collision of substrate & enzyme
- activation energy
how do enzymes reduce the activation energy
By straining the bonds in the susbtrate
intracellular enzymes
enzymes that work on the inside of a cell
extracellular enzyme
enzymes are released from the cell, to work outside the cell
extracellular enzymes example & use (1)
amylase digests starch into maltose
eexample of an extracellular enzyme & it’s use
trypsin breaks down protein s into smaller peptides
name 2 extracellular enzymes
amylase, tripase
name a intracellular enzyme
catalase
what is a intermediate molecule
formed from 2 or more substrates after being catalysed, then react further to give products
what is an enzyme substrate complex
enzyme molecule with substrate molecule in it’s actiev site, temporarily joined by non-covalent attraction. BEFORE reaction
what is an enzyme product complex
enzyme molecule with product molecule in it’s active site, temporarily joined by non-covalent attraction. AFTER reaction
what is the main suggestion that induced model makes that’s different from lock and key model
suggests active site isn’t a rigid structure
what bonds are present in the enzyme-substrate complex (in induced fit model)
hydrogen bonds, hydrophobic interactions ionic interactions, Van der Waals forces
what is different in the induced model to lock and key in terms of substrate bonding?
- subtle changes on amino acid’s R-Groups allows substrate to bond more effectively
what is different in the induced model after reaction?
- after reaction, products shape is slightly different to active site & can detach
what happens when pH changes & what effect does it have on the rate of enzyme activity
increase/ decrease in H+ ions from the optimum decreases the rate of reaction
how does H+ ions impact protein? (2)
- interferes with hydrogen and ionic bonding (due to charges) = disrupts the tertiary structure
- alters active site charges = substrate can’t bind
true or false not all enzymes have the same optimum pH?
true
true or false not all enzymes have the same optimum temperature?
false within THE SAME organism (37C body temperature)
optimum temperature defintiion
the temp at which the enzymes have the maximum rate of enzyme acticity
what are buffer solutions
solution that resist changes in pH by donating and accepting H+ ions e.g haemoglobin
what is the excess effect of temperature on enzymes
breaks hydrogen bonding holding tertiary structure.
does priomary structure of enzyme change by increase/decrease in tmeperature
no, peptide binds aren’t affected
what is the effect of temperature on enzymes
causes molecules to move faster; increases rate of collision & force with which they collide
what is the temperature coefficient
the temperature coefficient of a reaction measure of how much the rate of reactions increases with a 10C rise in temperature.