Protein & Lipids Tests: Biuret & Emulsion Test | A-level Biology | OCR, AQA, Edexcel

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Protein and Lipids Tests in a Snap! Unlock the full A-level Biology course at bit.ly/2tjNUH6 created by Adam Tildesley, Biology expert at SnapRevise and graduate of Cambridge University.
SnapRevise is the UK’s leading A-level and GCSE revision & exam preparation resource offering comprehensive video courses created by A* Oxbridge tutors. Our courses are designed around the OCR, AQA, SNAB, Edexcel B, WJEC, CIE and IAL exam boards, concisely covering all the important concepts required by each specification. In addition to all the content videos, our courses include hundreds of exam question videos, where we show you how to tackle questions and walk you through step by step how to score full marks.
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The key points covered in this video include:
1. Proteins - Biuret Test
2. Lipids - Emulsion Test
Proteins - Biuret Test
The Biuret test can be used to test for proteins by detecting the presence of peptide bonds. The sample to be tested is placed in a clean test tube. Biuret A (sodium hydroxide) is then added to the test tube. A few drops of Biuret B (copper (II) sulphate) is then added and the solution is gently mixed. If protein is present, the colour of the reagent changes from blue to purple.
Lipids - Emulsion Test
The emulsion test can be used to detect the presence of lipids. The sample to be tested is placed in a clean test tube. Ethanol is then added to the test tube and the solution is mixed thoroughly to dissolve any lipid. Water is then added to the test tube and mixed gently. A cloudy white substance indicates that lipids are present in the sample. This cloudy white substance appears as lipids are not soluble in water so they come out of solution and form an emulsion.
Summary
The Biuret test is used to test for proteins by detecting the presence of peptide bonds
Biuret's reagent turns from blue to purple if protein is present
The emulsion test is used to test for the presence of lipids
Lipid solutions form emulsions when water is added as they are unable to dissolve in water

Опубликовано:

5 авг 2024

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Комментарии : 26

@marwaalazri1510 4 года назад

1:57 lipids -emulsion test

@justsomeone2001 5 месяцев назад

Thanks a lot man ❤

@safaosman1547 Год назад

thank so much i understand this video and it help me to

@dylanjohns3326 4 года назад

These videos are extremely helpful and easy to follow. I will defo continue to use your videos for revision. Thanks 😁

@snaprevise 3 года назад

Thank you! Glad it was helpful! 😊

@princeronald162 3 года назад

i guess I'm kinda off topic but does anyone know of a good site to stream new tv shows online?

@ahmadbrendan5059 3 года назад

@Prince Ronald try FlixZone. Just search on google for it :)

@basmala2801 3 года назад

Thank you soo much this lesson was so hard ,I really understood everything THANKS

@snaprevise 3 года назад

You're very welcome! Glad it helped! Keep it up! 💯

@saadtahir4375 4 года назад

This is actually helpful and explained well

@snaprevise 3 года назад

Thanks! Glad it was helpful! 😊

@noorsabasherzad4345 3 года назад

this was really helpful and helped me understand it !

@snaprevise 3 года назад

Glad it was helpful! 😊

@shabadkaur6465 3 года назад

Awesome explanation!!!😉😉

@snaprevise 3 года назад

Thanks! 😃 Glad you liked it!

@wudehaileyesus3017 3 года назад

best explanation!

@snaprevise 3 года назад

Thanks! 💯

@raminraigamage5193 3 года назад

video was useful tks

@snaprevise 3 года назад

You are welcome! Glad it was helpful!

@aelamrani7525 Год назад

massive walking W

@unknown4822 4 года назад

for proteins, in my textbook it says that the copper (2) sulphate is very dilute (0.05%), does anyone know why?

@julianaminett7654 4 года назад

I was wondering the same thing. Basically, CuSO4 can form a complex with the peptide bonds in alkaline solution. So, the NaOH is there to make the solution alkaline, and the CuSO4 is there to show the colour change (and therefore indicate a positive test) To do simple tests, you don't have to use a lot because all we're interested in is whether or not there's proteins. We're not doing the test because we need the products of the reaction

@annabelle466 3 года назад

@@julianaminett7654 thank you! This has helped me a lot

@uhhm. 3 года назад

Is this A-level Biology because my school teaches this at secondary 2???

@vickyboulton9249 3 года назад

It gets taught at secondary because its taken into more detail at a level like every topic, so everything you learn in GCSE biology, A level takes it and makes sub topics from it with much more content. So the main topic gets made into 4 or 5 more topics that go more in depth and link together to make the bigger picture. Where we see the lipid emulsion test at GCSE we see the bonds, hydrolysis of bonds, products, chemical makeups involving condensation reactions, interactions with other molecules etc… At A level :)