enzymes

Question 1

enzyme reaction in terms of lock and key hypothesis

Answer 1

1. biological catalyst that Catalyse reaction by providing alternative pathway of lower activation energy to increase ROR
2. Identify lock (enzyme) and key (substrate)
3. Shape of substrate is complimentary to shape of active site
4. Substrate can fit into active site + form enzyme substrate complex
5. Enzyme catalyse reaction as the lower act energy allows rxn to proceed + form (products.)
6. products do not fit actuve site, released frm enzyme
7. Enzymes remain chemically unchanged at the end of reaction

Question 2

factors affecting enzyme reations

Answer 2

1. temperature
   - Rate of enzyme actions increases with increase in temperature
   - Usually, enzyme is twice as active for every 10 degree rise in temperature until optimum temperature is reached
   - Enzymes are inactive at low temperatures and denatured at high temperatures above opt temp so the substrate could not bind to active site bc active site shaped changed
   - Optimum temperature: temperature where enzymes are most active → results in highest rate of enzymatic reaction
2. pH
   - Different enzymes have different optimum pH at which their rate of reaction is fastest (eg: pepsin in stomach works best at pH 2 and trypsin in SI works best at pH 9)
   - Extreme pH denatures enzymes

Question 3

enzyme def

Answer 3

biological cataylsts made up of proteins
speeds up rateof chemical reaction
without being chemically changed at the end of reaction
work by lowering activation energy

Question 4

how to find name of enzyme

Answer 4

add -ase

Question 5

characteristics of enzymes

Answer 5

1. specific in action
   - Only a substrate that has complementary shape to the enzyme’s active site will be able to catalyse the chemical reaction.
   -this gives rise to lock and key hypothesis
   -Enzyme and substrate have specific molecular structure
   - Enzyme has an active site where substrate chemically binds to
2. sensitive to temp
3. sensitive to pH
4. remains chemically unchanged at the end of reaction
5. protein in nature
6. required in minute amounts
7. speeds up rate of chemical reactions

Question 6

limiting reactants in enzyme controlled reactions

Answer 6

1. concentration of enzyme
2. concentration of substrate

Question 7

what happen swhen enzyme conc is the limiting factor

Answer 7

all active sites on enzyme molecules are saturated
no free enzyme molecules to catalyse the reaction