Question

enzymes: substrate concentration
the concentration of the substrate can affect the rate of reaction
lets look at how this can happen
low → high
add 2 substrate molecules:
add 5 substrate molecules:
add 8 substrate molecules:
describe the rate of reaction:
describe how the rate of reaction has changed:
describe how the rate of reaction has changed:

Explanation:

• Enzymes are biological catalysts that speed up chemical reactions. The substrate is the molecule upon which an enzyme acts.
• When the substrate concentration is low (2 substrate molecules), there are fewer substrate molecules available to bind to the active sites of the enzymes. So, the rate of reaction is slow as there are not many enzyme - substrate complexes formed.
• As the substrate concentration increases to 5 molecules, more enzyme - substrate complexes can be formed compared to the low substrate concentration case. So, the rate of reaction increases (compared to the low substrate concentration of 2 molecules).
• When the substrate concentration further increases to 8 molecules, even more enzyme - substrate complexes can potentially be formed (assuming that the enzyme concentration remains constant initially). So, the rate of reaction increases further (compared to the substrate concentration of 5 molecules)

Answer:

• Add 2 substrate molecules: The rate of reaction is slow.
• Add 5 substrate molecules: The rate of reaction has increased (compared to 2 substrate molecules).
• Add 8 substrate molecules: The rate of reaction has increased further (compared to 5 substrate molecules).