Simulation · Biology · Class 11
What speeds an enzyme up or slows it down?
"What speeds an enzyme up or slows it down?" is a free, interactive Class 11 Biology simulation for NEET, built on the lesson "Factors affecting enzyme activity" in Biomolecules. Choose temperature, pH or substrate, then slide along the axis. The dot shows how active the enzyme is at that setting. Temperature and pH each give a peak at an optimum, with activity falling on both sides. Substrate gives a curve that rises and then levels off at Vmax; Km is the [S] at which velocity is half of Vmax.
From the lesson Factors affecting enzyme activity in Biomolecules. Change the values and watch what happens.
What speeds an enzyme up or slows it down?Biology · Class 11
The idea behind it
NCERT §9.8.4
- Conditions that alter a protein's tertiary structure change enzyme activity: temperature, pH, substrate concentration, and the binding of specific chemicals that regulate it.
- Enzymes work within a narrow range of temperature and pH. Each shows its highest activity at an optimum temperature and an optimum pH, and activity falls on either side of the optimum.
- Low temperature keeps an enzyme temporarily inactive, while high temperature destroys its activity because heat denatures proteins.
- As substrate concentration rises, reaction velocity rises at first and then levels off at a maximum velocity (Vmax) that more substrate cannot exceed. There are fewer enzyme molecules than substrate molecules, and once all are occupied no free enzyme is left for the extra substrate.
- When a chemical that binds to the enzyme shuts off its activity, the process is inhibition and the chemical is an inhibitor.
- A competitive inhibitor closely resembles the substrate and competes with it for the substrate-binding site, so the substrate cannot bind and activity falls. Malonate inhibits succinic dehydrogenase because it closely resembles the substrate, succinate.
- Competitive inhibitors are often used to control bacterial pathogens.
Questions
2 answers
- What does the "What speeds an enzyme up or slows it down?" simulation show?
- Choose temperature, pH or substrate, then slide along the axis. The dot shows how active the enzyme is at that setting.
- Is this simulation free?
- Yes. It is free and runs in the browser on a phone or a laptop. It belongs to the lesson "Factors affecting enzyme activity" in Biomolecules (Class 11 Biology).
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