Allosteric Regulation & Feedback Inhibition of Enzymes

An error occurred trying to load this video.

Try refreshing the page, or contact customer support.

Coming up next: Anabolism and Catabolism: Definitions & Examples

You're on a roll. Keep up the good work!

Take Quiz Watch Next Lesson
Your next lesson will play in 10 seconds
  • 0:00 Enzyme Regulation
  • 1:20 Allosteric Regulation
  • 2:49 Feedback Inhibition
  • 5:17 Lesson Summary
Save Save Save

Want to watch this again later?

Log in or sign up to add this lesson to a Custom Course.

Log in or Sign up

Speed Speed

Recommended Lessons and Courses for You

Lesson Transcript
Instructor: Christopher Muscato

Chris has a master's degree in history and teaches at the University of Northern Colorado.

Like miniature factories, our cells are always working, and they want to avoid producing too much or too little. The solution is in enzyme regulation. In this lesson we will explore one type of enzyme regulation, and see exactly how this works.

Enzyme Regulation

Imagine you are running a factory. What sort of things do you have to consider? You've got to make sure your machines work and create a product. You also want to make sure that you are producing the right amount. If you make too much, you're wasting resources. If you make too little, well that's just poor business skills.

Our cells are a lot like little factories. Resources come in, cells grow and divide, genetic material is reproduced—it's truly an industrial process. Now, to create a product, a factory needs machinery and so does the cell. This is an enzyme, a protein responsible for speeding up chemical reactions. Basically, complex molecules called substrates enter the cell, and enzymes break substrates down into smaller products that can be processed into energy or something else. But, like any other factory, the cell needs to make sure that production stays high enough to meet demand but low enough so as to avoid wasting resources. So, it has its own systems of enzyme regulation to control the productivity of enzymes and keep the cell running like a well-oiled machine.

Allosteric Regulation

So, we've got our enzyme, our little factory machine here that's speeding up chemical reactions and pumping out products. But, what if we need to change its pace? Say that the cell needs to save some energy and cut down production; how do we do that?

Well, you may notice that there are a few parts to this machine. This big opening here, that's called the active site, it's where the substrate binds with the enzyme to be processed. That's where enzyme function really occurs. But over here on this other side, we've got another slot. This is the allosteric site, where molecules can bind with the enzyme to change its shape and function. We call the control of enzyme productivity by binding a molecule to the allosteric site allosteric regulation.

Here's how it works. This specific enzyme can only process substrates that are a certain shape. The substrate comes in, binds to the active site, is turned into smaller products…bing bang boom. But, what happens when we bind another molecule with the allosteric site. The shape of the active site changes, and now the substrate won't fit. In this case, we used allosteric regulation to stop production, although this process can also be used to simply slow down enzyme function, or even to speed it up.

Feedback Inhibition

There are different ways that allosteric regulation can occur, but one of the most common involves the process of feedback inhibition, in which the final product of a series of reactions binds with the first enzyme to stop production. Here's how this works. Look at this assembly line. We've got a series of enzymes performing different chemical reactions to break apart a large substrate, and at the very end we have our basic products.

To unlock this lesson you must be a Member.
Create your account

Register to view this lesson

Are you a student or a teacher?

Unlock Your Education

See for yourself why 30 million people use

Become a member and start learning now.
Become a Member  Back
What teachers are saying about
Try it risk-free for 30 days

Earning College Credit

Did you know… We have over 200 college courses that prepare you to earn credit by exam that is accepted by over 1,500 colleges and universities. You can test out of the first two years of college and save thousands off your degree. Anyone can earn credit-by-exam regardless of age or education level.

To learn more, visit our Earning Credit Page

Transferring credit to the school of your choice

Not sure what college you want to attend yet? has thousands of articles about every imaginable degree, area of study and career path that can help you find the school that's right for you.

Create an account to start this course today
Try it risk-free for 30 days!
Create an account