Biology: Can a low pH denature an enzyme or is a just a high pH?

I know a really high pH beyond the optimum temperature would denature an enzyme but can a REALLY low one do just the same? For example the enzymes in the small intestine work their best at a pH of around about 7.5 (according to bbc bitesize) but image in the pH was too low like one will those enzymes in the small intestine denature?

Reply 1

whydoidothis?

21

high can denature, however some enzymes work slowly at low temperatures, ive only done Gcse biology so that's what I know lol.

Reply 2

aiyshaxo

1

From what I know low pHs don't denature enzymes but, as the person above me said, they make the enzymes work a lot slower

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Reply 3

Munrot07

18

Original post by Tcool

I know a really high pH beyond the optimum temperature would denature an enzyme but can a REALLY low one do just the same? For example the enzymes in the small intestine work their best at a pH of around about 7.5 (according to bbc bitesize) but image in the pH was too low like one will those enzymes in the small intestine denature?

Yep, pHs above and below the optimum can denature the enzymes for the same reason :smile:

Reply 4

AlexeiLipov

5

Enzymes are sensitive to conditions other than their optimum.
Higher pH = Denature
Lower pH = Denature
Higher temperature = Denature
Lower temperature = Work way too slowly to keep up the reactions in the body.

To answer your question:
Yes, a low pH can also denature an enzyme. It doesn't matter if it is a higher pH than normal or a lower pH than normal; if there is a pH change then it will change the shape of the active site and render the enzyme useless.

Reply 5

Tcool

OP

2

Original post by AlexeiLipov

Enzymes are sensitive to conditions other than their optimum.
Higher pH = Denature
Lower pH = Denature
Higher temperature = Denature
Lower temperature = Work way too slowly to keep up the reactions in the body.

To answer your question:
Yes, a low pH can also denature an enzyme. It doesn't matter if it is a higher pH than normal or a lower pH than normal; if there is a pH change then it will change the shape of the active site and render the enzyme useless.

Thank you

Reply 6

Tcool

OP

2

Original post by Munrot07

Yep, pHs above and below the optimum can denature the enzymes for the same reason :smile:

Tanx!

Reply 7

AlexeiLipov

5

Original post by Tcool

Thank you

No problem! :smile:

Good luck in your biology GCSE :biggrin:

Reply 8

Tcool

OP

2

Original post by AlexeiLipov

No problem! :smile:

Good luck in your biology GCSE :biggrin:

Tanx that's very nice of you. Good luck to you too if you've got to take or have taken in any exams :smile:

)

Reply 9

sam_aggy96

At a high pH because the active site changes which causes the substrate to become unable to bind with the active site. Therefore denaturing the enzyme

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Reply 10

C0balt

16

Yes it does denature.
However keep in mind that the optimal pH of protease in stomach (pepsin) is very low as stomach has acid inside.

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Reply 11

interstitial

18

It can change the shape of the active site so the substrate is not able to bond with it. The effect of the pH depends on the type of enzyme, pepsin for example (in the stomach) works best at low pH's but others might not.

Reply 12

interstitial

18

Original post by AlphaNick

They are denatured at low pHs, its temperature where the rate of reaction simply deviates when it is too low.

Are you sure about this? I remember being told that temperature can also permanently denature enzymes by changing the shape of the active site :s-smilie:

Edit - Whoops, you were talking about low temps, my bad

Edit 2 - I guess it could still have a permanent effect if the enzyme was in a solution :holmes:

(edited 9 years ago)

Yes they can.

Original post by AlphaNick

They are denatured at low pHs, its temperature where the rate of reaction simply deviates when it is too low.

Oops, maybe I don't know as much about biology as I thought I did lol

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Reply 15

thegodofgod

19

Original post by Tcool

I know a really high pH beyond the optimum temperature would denature an enzyme but can a REALLY low one do just the same? For example the enzymes in the small intestine work their best at a pH of around about 7.5 (according to bbc bitesize) but image in the pH was too low like one will those enzymes in the small intestine denature?

Changing the pH of an enzyme solution will alter the ionisation of the R groups in amino acids (amino acids polymerise to form enzymes). These ionisation changes may affect attraction / repulsion between different amino acids, and therefore, may change their arrangement in space. This will, therefore, change the 3D shape of the enzyme, and therefore, may change the 3D shape of the active site. If the shape of the active site is altered, the substrate may not be able to bind as efficiently, and thus, the rate of reaction may be reduced.

Reply 16

AlexeiLipov

5

Original post by thegodofgod

Changing the pH of an enzyme solution will alter the ionisation of the R groups in amino acids (amino acids polymerise to form enzymes). These ionisation changes may affect attraction / repulsion between different amino acids, and therefore, may change their arrangement in space. This will, therefore, change the 3D shape of the enzyme, and therefore, may change the 3D shape of the active site. If the shape of the active site is altered, the substrate may not be able to bind as efficiently, and thus, the rate of reaction may be reduced.