AS Biology - Structure and function of plasma membranes (OCR A Chapter 5.1)

[@Nunu-jc1vl]

Been using a couple of your video for as mocks next week and honestly you are a lifesaver. I’ve understood soo much watching your vids thank you. I’ll defo be seeing this channel next year for a level topics

[@karimaakter2598]

My As level bio exam is day after tomorrow and here i am watching your videos..A BIG THANK YOU FOR SAVING MY LIFE!1😭😭🥺💖💖✨

[@JimJam-ju6vn]

how did you do?

[@vswlondon8070]

Glad I found your channel as this is so very helpful! Thanks so much!

[@BioRach]

Glad you found it helpful! Thanks for watching :)

[@leonelryker6834]

Instablaster...

[@jasminewillicott2521]

I found this so helpful. Thank you!

[@exclusiveR-22]

Can you explain more about the function of extrinsic protein as you didn’t mentioned much about it.

[@elishacoen9391]

Hi, are you able to expand on this a little and clarify the distinction between glycoproteins and glycolipids please? My textbook divides the functions up between them, and internet sources say contradictory things! Thank you. I find your videos very helpful and valuable :)

[@BioRach]

The difference is mainly in the structure (as implied in the name). There isn't a great deal of difference in terms of their functions - they pretty much do the same thing because they both have the carbohydrate chain sticking out! In exams, you can say that they both act as receptors/involved in cell signalling, communication and recognition. Hope this clarifies things! Thanks for watching :)

[@elishacoen9391]

@@BioRach Thank you :)

[@tutaakad7736]

Hey I love your videos. I just rlly wanted to ask whether glycoproteins is considered extrinsic or intrinsic and why - a lot of books and marks scheme contradict this. Thanks

[@tutaakad7736]

Will Baldwin thanks you sooooo much

[@BioRach]

Absolutely! I think it may depends on the location of the protein section of the glycoprotein - if it's embedded within the membrane then I'd say it's an intrinsic protein; but if it is on the surface then extrinsic. Hope that helps :)

[@ghsjgsjg53chjdkhjydhdkhfmh74]

Thank you!!

[@mdmoniruzzaman7103]

Could you please explain -what is the difference between Carrier protein and channel protein? Are are integral proteins channel proteins?

[@aishaqureshi597]

Channel proteins are used to provide a hydrophilic channel for passive movement of polar molecules and ions by facilitated diffusion. Carrier proteins are used to transport larger lipid insoluble molecules like glucose/amino acids also by facilitated diffusion or by active transport. Yes channel proteins are integral proteins :)

[@yashfeenfarooqui1299]

wow this was very helpful, thanks a lot

[@jadagill8113]

Hi just wanted to clarify whether cholesterol makes the membrane more or less fluid?

[@BioRach]

It's a tricky one - it could go either way depending on the type of cholesterol and where they are found in the membrane. That's why in exam mark schemes and when taught, we always just keep it simple as "cholesterol maintains fluidity" 😬

[@winlarter4235]

Hi Rach what is meant by concentration gradient please ? :)

[@BioRach]

It means a difference in concentration. A gradient describes the slope of a line, where one end is high and the other end is low. It's the same concept in concentration gradient - one side has a high conc, the other side has a low conc.

[@winlarter4235]

what is a bilayer please ?

[@RS-fv9th]

Yasmine Dova A bilayer is the two layers of phospholipids. In the drawing, thats in the video the circle with two lines are the phospholipids. The tails face each other and the heads face outwards. Because theres 2 layers of them, its called a bilayer.

[@BioRach]

Thanks for replying! :)

[@Cloudy.419]

What are the examples of extrinsic protiens...? In the text book, one of the answer for the summary questions says that an example of extrinsic protein is a glycoprotein....but glycoprotein is an intrinsic protein..... Im so confused 😰

[@hollyjames6565]

it might be extrinsic because they are technically not embedded in the membrane but sticking out of the membrane. This can be seen on the diagram she had drawn. Hopefully this helps!

[@ghsjgsjg53chjdkhjydhdkhfmh74]

Can you please make more videos on Transport in Animals?? Thank you so much!!!

[@BioRach]

I've just made some on oxygen and carbon dioxide transport, like the Bohr effect etc.! Check back soon :) thanks for watching!

[@michaelphillips9185]

tysm this was very helpful :)

[@winlarter4235]

hi what does non-polar means please ?

[@BioRach]

A non-polar molecule evenly shares the electrons between the atoms (eg. CO2, O2, CH4). A polar molecule does not, as the electrons are more attracted to at least one of the atoms within the molecule. This is due to the atom's higher electronegativity (the ability to attract electrons stronger). Examples include H2O (electrons spend more time orbiting around O than H). In the context of this chapter, non-polar molecules are also hydrophobic (water hating); polar ones are also hydrophilic (water loving).

[@connieforbes6212]

thank you so muchh!!!

[@MiffySkittles]

Love your videos! Any tips on what to do after having watched your vids to just consolidate everything?

[@khadija2739]

Do past papers on pmt on the topic and other forms of active recall

[@BioRach]

Definitely do lots of retrieval questions!

[@R20039]

hi, what are some examples of extrinsic proteins? thank you for your helpful videos :)

[@argonaut7769]

Cholesterol

[@thophop6377]

@@argonaut7769 that's intrinsic...

[@neithonosmani9783]

Another comment asked this too. She said it depends on the location, if it’s embedded in the membrane then it’s intrinsic but if it’s located just on the surface then it’s extrinsic.

[@timmy18135]

Why is both this and the ionized gas called plasma?

[@dampy2006]

Did something happen while you were away for 4months? I missed your vids 😋

[@BioRach]

Haha summer + busy start of the new school year!! Hopefully can get back to more filming soon! Thanks for watching :)

[@mohammadhosseinasadifard9973]

Helpful thankss