EnzymesEnzymes

04/18/2304/18/23

ENZYMES

I.I. PropertiesPropertiesA.A. Highly SpecificHighly Specific

1.1. Each reaction has own specific enzymeEach reaction has own specific enzymea)a) = = Lock and key hypothesisLock and key hypothesis

2.2. Sometimes enzyme molecules “tweak” reactantsSometimes enzyme molecules “tweak” reactantsa)a) = = Induced fit hypothesisInduced fit hypothesis

B.B. Speed up reactionsSpeed up reactions1.1. Lower energy of activationLower energy of activation

ENZYMES

2.2. All biochemical reactions need to reach certain energy All biochemical reactions need to reach certain energy level to reactlevel to react

a)a) = = Energy of activationEnergy of activation

3.3. If activation energy is not reached, reaction will not If activation energy is not reached, reaction will not occuroccur

4.4. With enzyme activation energy is lowered so that With enzyme activation energy is lowered so that reaction will occur at body tempreaction will occur at body temp

5.5. With out enzymes, cell reactions would not occur at 37°With out enzymes, cell reactions would not occur at 37°

ENZYMES

C.C. Most enzymes are proteinMost enzymes are protein1.1. Coded for by DNACoded for by DNA

D.D. Enzymes are affected by pHEnzymes are affected by pH1.1. All have optimal pHAll have optimal pH

a)a) Catalase = pH 8Catalase = pH 8

b)b) Stomach enzymes = pH 1-2Stomach enzymes = pH 1-2

E.E. Enzymes have optimal temperatureEnzymes have optimal temperature1.1. Most operate best at 37°Most operate best at 37°

2.2. Some can work at higher temperatures Some can work at higher temperatures

3.3. All slow at cool temperaturesAll slow at cool temperatures

4.4. All reactions slow when exposed to cool temperaturesAll reactions slow when exposed to cool temperatures

5.5. Enzymes denature if temperature is too hotEnzymes denature if temperature is too hota)a) Permanent damagePermanent damage

F.F. Enzymes can be inhibitedEnzymes can be inhibited1.1. CompetitiveCompetitive

2.2. Non “Non “