This document discusses enzymes, including their structure, function, and factors that influence their catalytic activity. It notes that enzymes are composed of proteins and cofactors/coenzymes, and that their active sites can bind substrates using lock and key or induced fit mechanisms. Temperature, pH, substrate and enzyme concentrations, and inhibitors can all impact an enzyme's function by altering its structure or ability to bind substrates. Inhibitors are useful medically as drugs but can also be toxic if they block critical enzyme pathways like cellular respiration.

1. Enzyme Metabolisme
Diagram pita yang
menunjukkan karbonat
anhidrase II. Bola abu-abu
adalah kofaktor seng yang
berada pada tapak aktif

2. Learning Objectives
 To description structure, function and
characteristic of enzim
 To explain enzim mechanism
 Mention kinds of factor that can influence
enzim mechanism
 Kinds of inhibitor for enzim catalyst
KD 4.1 Describe the function of enzymes in metabolic
processes

3. Structure
Inhibitor
The factor
that influence
Function

4. Catalyst Function
 The substance can speed up the reaction but that
substance unreacted
 Reaction without the catalysts require a high activation
energy, reaction with the catalyst requires a lower
activation energy
 Metals, spurring activity of the enzyme: Mg, Mn, Co, Fe
 Heavy metals, inhibiting enzyme activity: Pb, Cu, Zn, Cd,
Ag

5. Catalyst structure
 enzymes composed of two components:
proteins (apoenzim) and non-protein
(prosthetic group) called holoenzim
◦ Apoenzim, are labile (easily changed),
affected by temperature and acidity
◦ Prosthetic group, The part that is not a
protein, consisting of cofactors or coenzymes
 Cofactor derived from inorganic molecules, namely
metals:iron, copper, and zinc.
 Coenzyme is composed of complex organic
compounds, such as NADH, FADH, coenzyme A,
and vitamin B.

6. Mechanism of Catalyst
 LOCK AND KEY
 The enzyme is
exemplified as a
lock because it
can bind to the
substrate
 Substrate is
exemplified as
the key because
it can open the
side of the active
enzyme

7.  INDUCED FIT
 Side of the active
enzyme is flexible
so it can adjust to
the shape of the
substrate

8. Temperature
Acidity Change
Substrate and catalyst
enzim consentrate
Faktor yang
mempengaruhi
kerja enzim

9. Temperature
 High temperatures can cause enzyme damage
(denaturation)
 Low temperature can inhibit the action of the
enzyme but does not damage the structure of the
enzyme
 Warm-blooded and human enzymes work most
efficiently at a temperature of 37o C, while the
enzyme cold-blooded animals at temperatures
25o C.

10. Acidity
 Changes in pH can influence key amino acid
changes in the enzyme active thus blocking
the active side in combination with the
substrate.
 All enzymes are sensitive to pH changes, and
switches off at very low pH environment
(strong acid) and high pH (strong base)
 Example, the pepsin enzyme has an optimum
pH of 2, whereas the trypsin enzyme has a
pH optimum 8.5

11. Usefulness inhibitor
 Inhibitors are used as medicine
◦ An example is the inhibitor that is used as a
drug aspirin.
◦ Aspirin inhibition enzyme COX-1 and COX-2
that produce the inflammation messenger
prostaglandin, thus it can suppress
inflammation and pain.
 Toxic enzyme inhibitors.
◦ Cyanide is an irreversible inhibitor of the
enzyme, will join the copper and iron in the
enzyme active site of cytochrome c oxidase
and blocks cellular respiration

12. SUBSTRATE AND CATALYST ENZIM
CONSENTRATE
 Comparison of the amount of enzyme
and substrate must be in accordance
 Enzyme and substrate is much less
then the reaction will be slow

13. Catalyst enzim inhibitor
 Changes in the
enzyme active side
because there is not
a substrate inhibitor
that can bind to the
active

14. Catalyst enzim inhibitor
 inhibitor structurally
similar to the substrate
so that the competition
for the active side
 if the inhibitor binds to
the active side will not
be formed products