PROTEINS & ENZYMES- AQA A LEVEL BIOLOGY + EXAM QUESTIONS RUN THROUGH 

00:49 = Amino acid structure and polypeptides 03:59 = Protein structure (primary, secondary, tertiary & quaternary) 07:40 = Biuret's test for protein 08:43 = How enzymes work and the induced fit model 11:07 = How temperature affects enzyme activity 12:35 = How pH affects enzyme activity 13:54 = How enzyme concentration affects enzyme activity 15:11 = How substrate concentration affects enzyme activity 16:02 = Competitive inhibition of enzymes 17:20 = Non-competitive inhibition of enzymes 18:26 = Exam questions and mark schemes

Thank you so much for this video, and for explaining the mark scheme it was so helpful!

This video was so helpful! I've got a biology test on it tomorrow, so this really helped me. Thank you 👍🏻

Thank you so much! I have an enzymes test this week so this is very useful :)

Girl, you have just nailed the job!

for the last question could i explain the curves plateau because at higher temperatures(outside the optimal range) the hydrogen and ionic bonds in the enzymes tertiary structures are affected resulting in change in shape of active site, therefore the enzymes used in the reaction wont be able to form E-S complexes and therefore rate of reaction slows down, or does it have to be because substrate is used up.

Great vid🥳

hello, Can I ask if you'd just need to assume that enzymes are made up of only one polypeptide chain for A-level AQA? (because it is always described as in their tertiary structure)

thank you so much you r a blessing

Hey there , thank you so much for the video it’s really helpful I was wondering about the answer in 23:29 you wrote that cyanide acts as a competitive inhibitor . Instead isn’t the antidote what acts as the competitive inhibitor or is it the substrate/ cyanide itself that acts as the competitive inhibitor?

at 30:29 you said it was a comparative question but how would you know to compare because it says what is the effect so how would you know to not just explian the effects of each test and know to compare them to eachother is there any command words im missing or not understanding

Hey how many amino acids sequences does one polypeptide chain contain?

for the biuret test. i know to use biuret's reagent but cgp revision guide memtioned adding sodium hydroxide to make test solution alkaline and then adding copper (II) sulfate solution. is that really necessary to know for biology as year 1 or even in general?

How did you know it was a comparison question for q5 c ii?

would need to know other like forms of proteins like gobular and fibrous and what they contain ?

what is the difference between enzyme-controlled and enzyme-catalysed reactions? thanks,

Hey, can you recommend me any channel for As physics and chemistry, like yours