Download Enzyme Meeting Words Discussion

ENZYME WHITEBOARD ACTIVITY Verby- 7th period
Provide a complete explanation of how enzymes function. In your discussion, be sure to address the
following six points:
1. Amino acid structure—what do all amino acids have in common, what makes them different.
All amino acids have an amino group, a carboxylic acid group and an R group. The R group has
twenty different types, which will determine the amino acid you have. And several amino acids in a
chain create a protein. The type of protein depends on the sequence and location of the different
amino acids in the chain, the repeatable patterns of alpha helix and beta sheets, the bending and
folding of the peptide chains due to the interactions between the amino acids and the interactions
between the globular proteins. These proteins make up enzymes.
2. Diagram an amino acid chain and suggest how it might fold into a protein relative to the chemical
properties of each of the amino acids.
Folding of a polypeptide chain will be determined interactions between the amino acids of the chain.
The polarity and charge of the different amino acids will determine the interactions.
Hydrophilic (polar) amino acids will move towards the outside of the protein where water is,
hydrophobic (non-polar) amino acids wil fold to the inside of the protein to avoid water. Positively
charged amino acids can form ionic bonds with negatively charged amino acids. Polar amino acids
can attract other polar amino acids and some polar amino acids can form hydrogen bonds with other
polar amino acids.
3. Indicate the active site of your protein and why a given substrate would tend to enter. Discuss how
“Lock and Key” is a useful model for describing this characteristic of enzymes.
The active site of the enzyme is where the substrate bind and interact. In the lock and key model the
enzyme is the lock, the active site is the keyhole and the substrate is the key. This means that in
order for the substrate and to react, the substrate must fit the shape of the active site. This is why
the active site of the enzyme is specific for only one substrate and can only catalyze one reaction.
4. Enzymes cause stable molecules to react by lowering the activation energy required for the
reaction. Indicate how the enzymes account for this required activation energy and how this action
can be thought of by the “Induced Fit”model of enzyme activity.
Enzymes speed up the chemical reaction by lowering the activation energy of exothermic/
sponataneous reactions. The induced fit model of enzyme activity states that when a substrate binds
to the active site of the enzyme, the enzyme changes shape slightly. This change in the shape of
the enzyme puts strain on the bonds of the substrate and weakens the bonds. This weaken of the
bonds of the substrate results in lower activation energy and thus speeds up the rate of the
reaction.
5. Indicate how high temperatures might cause enzymes (proteins) to unravel or denature.
After a certain temperature, an enzyme starts to denature. This occurs because after the certain
temperature, the amino acids in an enzyme lose their ability to interact with other amino acids,
through things like polarity and hydrogen bonding, due to the high temperature they are facing. This
causes the tertiary structure of the protein to unravel. This causes the active site to lose it's shape,
and thus, the enzyme is no longer functional to catalyze a reaction.
6. Indicate why extremes of pH can cause enzymes (proteins) to unravel or denature.
Each enzyme works best at a specific range for pH. If outside of this optimum range; the enzyme
can denature. Extreme pH's can disrupt the interactions between the amino acids of the enzymechanging the protein structure of the enzyme. If an enzyme has lost the shape of it's active site it
can no longer function as an enzyme to catalyze a reaction.