Enzyme Inhibitors | A-level Biology | OCR, AQA, Edexcel
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- čas přidán 8. 04. 2019
- Enzyme Inhibitors in a Snap! Unlock the full A-level Biology course at bit.ly/2I9DVh4 created by Adam Tildesley, Biology expert at SnapRevise and graduate of Cambridge University.
The key points covered of this video include:
1. Enzyme reaction rates
2. The effect of temperature
3. The effect of pH
4. Enzyme and substrate concentrations
Enzyme Inhibition
We have seen how enzymes can be activated by cofactors. Enzymes can also be deactivated by molecules called inhibitors. Inhibitions are any molecule that reduces or stop a reaction. Adding a small concentration of an inhibitor will reduce the rate of reaction. If an excess of an inhibitor is added to a solution then the reaction may be prevented completely.
Competitive Inhibitors
One type of inhibitor is called a competitive inhibitor. It fits into the active site of an enzyme instead of the substrate. These inhibitor form a physical barrier that prevents the formation of enzyme-substrate-complexes. Because both inhibitor and substrate can fit into the active site they compete with each other for the enzyme.
Non-Competitive Inhibitors
The other type of inhibitors is non-competitive inhibitors. Non-competitive inhibitors bind to a separate part of an enzyme called its allosteric site. Binding of a non-competitive inhibitor causes a conformational change in the enzyme. This change alters the shape of the enzyme's active site so that it is not complementary with its substrate. Because these inhibitors do not bind to the active site they do not compete with substrates - hence their name.
Comparing Enzyme Inhibitors
Competitive and non-competitive inhibitors work in different ways. Non-competitive inhibitors have a powerful inhibition effect. Competitive inhibitors have a less powerful inhibition effect. A graph of both inhibitor effects is a good way to compare the two. Most competitive inhibitors bind reversibly. Most non-competitive inhibitors bind permanently. This table summarises the differences between competitive and non-competitive inhibitors.
End-Product Inhibition
We have already seen how enzymes can work together to complete metabolic processes. Most of the time a cell will only want a certain amount of a molecule being produced. In some cases, one of the products acts as an inhibitor to another enzyme in the pathway. When the inhibitor non-competitive and the last product in the pathway it is called end-product inhibition. If the concentration of the final product is high, then more inhibition will occur. Greater inhibition will lead to a decrease in the amount of end product being produced. Inhibition also decreases if the concentration of the end product decreases. This is an example of a negative feedback loop which ensures the concentration of a product stays roughly constant.
Summary
Enzyme activity can be reduced or stopped with inhibitors
Non-competitive inhibitors bind to allosteric sites and have a strong inhibition effect
Competitive inhibitors bind to active sites and have a weaker inhibition effect
End-product inhibition relies on non-competitive inhibition to keep the concentration of metabolic products roughly constant in a cell
night before mock lets go
did you pass
@@am-ew2vz yes I did
@@dylanc5835 I got my mocks in January now. I'm scared
OMG ME TOO. Even though u were a year ago. BUT I AM STILL SCARED
@@mory1265 you'll do great, think about where u wanna be in 5 years and about how these grades will help to get u there and you'll be motivated all night 😂
9:30 that quick correction recovery
Yeah how tf was that so quick lmao
Thank you for explaining things so visually, it really gels with my brain 👏👏👏
You're welcome! Happy to help! 🙌
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12:13, I guess they forgot to cut out him repeating the "negative feedback loop" part lol. GREAT VIDEO THO! VERY HELPFUL THANKSSS!!
Doing AS for the first time in high school and your videos really helps
First video of yours that I've watched. Extremely clear and comprehensive :) Loved the way that you used graphs to facilitate understanding
Who al notived that at 12:11 the part was supposed to be cut but wasnt
That photo he used for non-competitive inhibitors.. ouch, shots fired!
Wonderfully explained mate, really appreciate the animations as well
Thanks! Glad you liked it!
Very helpful and clear, thank you!
I love this video, it was so perfect!! Thank you so much!!
Thank you and you're welcome! We're glad you liked the video! 👍
You are an excellent teacher
More power to you Sir👏
Great video bro..helped a lot
Is there a video going over the graphs for enzymes we have to know?
Thank you for these amazing lessons
You're truly a life saver
You're very welcome! Glad you like them! 🐱🏍
Incredible. Adam is wonderful.
Thank you! 😊
Shoutout to Year 12 biology.
ye some people like you suck at it
Justin van den Hout I swear to god you are some ugly child. Like how can you be so bad to look at. God damn
Justin van den Hout you are such a piece of shit you 11 year old baby...
Can you please make a video on the starch amylase enzyme experiment to measure the rate of reaction
I've seen a hundred videos but none are explained like this and none are as helpful as your videos which are exactly what I need for my Alevel syllabus
thanks! very helpful
Thanks for teaching us!! Your voice are very soothing tooo 😁😁
You're welcome! Glad you liked it! 😊
These are some good videos, thanks.
Thank you too! 😊
What about affinities?
At 1:30 if you add an "excess of an inhibitor" surely the reaction rate will not completely reach zero? Does it not just tend towards zero instead? - without actually reaching it? Clarification would be appreciated.
can a non compietive inhibitor be reused?
Thankssss!!! That helps me a lot for my biology quiz tomorrow🙊👍👍
Happy to help! Good luck!! All the best!
So you can say Le Chatelier's principle is based on end product inhibition or vice-versa?
Very well explained. Thank you for this, diagrams were great too
You are welcome! Glad it was helpful!
@@snaprevise yay, you guys reply now! Haha once again, great content
Really good at explaining omg
Thanks! Glad you think so! 😊
This was legendary 👌🏼👌🏼
You're legendary! 😎
is a cofacter a substrate?
these videos save my life
🐱🏍
sir thank you so much this helped me a lotttt!!!!!!!!!!!!!!!!!!
Glad to hear that! Most welcome! 😊
thank u sir
you are so helpful thankyou so much
You are so welcome! 😊
Perfect
For what purpose, enzymes activity stop or reduce through inhibitors?
To prevent the concentration of product reaching toxic levels in the cell. Hence there is negative feedback to ensure the concentration of product stays at a similar level
THANK YOU
You're welcome!
I really like the word allosteric site idk why
I haven't found summary section in any of your videos in spite of its regular mention in the initial part of all the videos. Is it that there has to be another kind of access to these videos (which I do not see any provisions/options offered) to see the summary section? Or, is it something else? Please clarify.
The videos with the summaries at the end can be found on our website snaprevise.co.uk. I suggest that you go and check it out! You can also find there some free resources like revision guides, quizzes, cheatsheets, and a lot more! 😊
@@snaprevise alright, I'll go through the link to see how it works, thankyou!
I like it
In end product inhibition are the changes made by the inhibitor not permanent then? Because it reactivates when it needs to, but i thought the changes made by non-comp were permanent?
it says its "mostly" permanent
Thank you
You're welcome! 😊
Can't understand the end product inhibition 😐😐
thankyou so much
You are so welcome! 👍
Copyright for animation or text?
I think they make the animations and text themselves (not sure tho) also if you include the resources you got the animations from I don’t think it’s taken down
Very good video 👍🏼😊😊😍😍🥰🥰
Thank you 🤗
thanks
You're welcome! 💖
from 2022
love ya
Wonderfully explained 👏
Thank you 🙂 Glad you liked it! 🙌
lmfao did they just do a loop effect for the phrase "negative feedback loop"
Mids from 3rd Jan 😖😶
Xw