Thursday, 3 January 2013

2.9 understand how the functioning of enzymes can be affected by changes in temperature, including changes due to change in active site

As heat increases kinetic energy increases, this means enzymes and substrates more around more so they are more likely to 'bump into' one another (collide) and bind. This means that as heat increases so does the amount of reactions an enzyme catalyses.

However if the temperatures are too high it will denature enzymes, so they can't function. Because the energy breaks the bonds that hold the shape of the enzyme: without these the structure will be distorted, which will mean the active site won't be able to bind with the substrate to break it down.

Note the active site is the area on an enzyme that binds with a substrate to break it down; it is the lock in the lock and key theory.

Optimum temperature is in between these two scenarios, where there is lots of energy from heat but not enough to denature the enzyme. It is different for different enzymes.

8 comments:

  1. thank you so much for doing this! It's really helpful :) xxxxx

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  2. You missed out the key information: Higher temperature means higher average kinetic energy for substrate and enzyme: means substrate and enzyme collide more frequently: means reactions happen more frequently. Optimum temperature is around 40 degrees C.

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    1. You are wrong sir, High temperatures will denature enzymes, so they can't function. Because the energy breaks the bonds that hold the shape of the enzyme: without these the structure will be distorted, which will mean the active site won't be able to bind with the substrate to break it down.

      Note the active site is the area on an enzyme that binds with a substrate to break it down; it is the lock in the lock and key theory.

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    2. All hannah missed out is the optimum temperature, but it doesnt mention optimum temperature in 'understand how the functioning of enzymes can be affected by changes in temperature, including changes due to change in active site' i believe.

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    3. You are actually all right haha, I'll change the post to encompass all :)

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  3. Hannah should have included different temperature such as low temperature,room temperature and high temperature. She should also use optimum temperature definition

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    1. This comment has been removed by the author.

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  4. more at

    http://igcse-biology-notes.blogspot.hk/2017/06/29-understand-how-functioning-of.html

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