Enzymes Flashcards
what is metabolism
the sum of all cellular reactions
what is an anabolic reaction and an example
energy used and stored to create bonds (eg protein synthesis)
what is a catabolic reaction and an example
energy released to break bonds (eg cell respiration)
what is an enzyme
a biological catalyst that speed up reactions in living systems without altering anything (reusable)
what is an active site
enzymes have active sites that are unique 3D shapes that binds the substrate, each enzyme is unique for only one substrate
what is activation energy
initial energy required to start a reaction
how do enzymes increase reaction rates by lowering activation energy
- binding the substrate tightly to weaken bonds
- positioning substrates in the right place for the reaction to proceed
why do chemical reactions occur in several steps controlled by enzymes
- to control amount of energy released at each step
- to lower amount of activation energy required
- so that intermediate products can be used in other reactions
what are 5 factors affecting enzyme activty
temp, pH, cofactors, enzyme/substrate concentration, inhibitors
explain the affect of temp on enzyme activity
higher temp = more energy to react, too high = enzyme denatures
explain the affect of pHon enzyme activity
enzymes each have an optimal pH that they react well too, too high pH = denature
explain the affect of cofactors on enzyme activity
co enzymes - molecule that binds to reshape substrate to fit in
explain the affect of enzyme/substrate concentration on enzyme activity
enzyme: higher concentration = rate of reaction increases because more chance of binding
substrate: more substrate = less active sites
explain the affect of inhibitors on enzyme activity
competitive - binds and blocks substrates from binding
non-competitive - attach on enzyme (not active site) and distort enzyme and therefore active site shape