Hello, this is Ms Beh and I teach Cambridge AS and A Level 9700 Biology! :)
During the pandemic, I made many videos for my own students for online learning, so i thought i might as well share it with the world. This channel aims to make education just a little more accessible to all. This channel now has a COMPLETE COLLECTION of videos from ALL chapters according to the new 2022-2024 syllabus!
Cambridge A-Level Biology notes, worksheets, topical past papers, videos without ads, and other resources can be now be purchased by chapter on www.genesisorigo.com/cambridge-a-level-biology/
How to Enrol? www.genesisorigo.com/a-level-resources-guide-to-enrollment/
Contact / follow me on: Email - behlogy@gmail.com RU-vid - www.youtube.com/@behlogy Instagram - instagram.com/behlogy/ TikTok - www.tiktok.com/@behlogy
36:01 I don't really get how risk of spreading antibiotic disease to other bacteria is a problem.. I also don't get how antibiotics being less effective in disease-causing bacteria is relevant in this case because why would someone use them as vectors instead of normal bacteria? for 41:01, what you mean by "chemically identical to human insulin" is the human insulin produced from the recombinant DNA genes is chemically identical to the human insulin in our body right? And 43:13 how does bacteria's organelles not being membrane-bound make its proteins not able to be genetically modified?
Hello, could you pls explain why we have to calculate the mean of the time taken for each test (When time taken is given for each test in the Q) and using that mean value to calculate the rate of reaction
Hey there, Paper 5 Essential Guideline is now available via genesisorigo.com/cambridge-a-level-biology After making an account, you will need to "enrol" for the free resource. More instructions can be found here genesisorigo.com/a-level-resources-guide-to-enrollment - Ms Beh
Hi Miss Beh🤗 I unfortunately can't view the next video (the one on measles). RU-vid is saying that it's unavailable and hidden would you be able to repost it or send it to me in some way please. These videos are extremely helpful and I'm kinda bummed out about missing one.
Imagine them swimming around in a pool with their heads on the surface, little legs underneath hahah (but pls use that phrasing. that phrasing is markscheme standard)
while describing about the reciprocal thing in textbook there is written you do not need to understand how to do this. So can i just remember only the fact that the graph is obtained only when few experiments are done and at some point of all experiments the initial rate of reaction happens at constant rate for all experiments?
Oh cool, i havent noticed that line in the textbook. I get why you made that assumption and i can say that's true for graphs that is rate against [S] and [P]. But not for temperature and pH.
Hi ma'am i have a question, when we say hydrogen bonds occur between same base pairs what do we mean? as in the same typa bond like A with T repeating im confused
Same base pairs, as in the same pair. So A binds with T. C binds with G. Sorry english is weird/unclear sometimes. Please avoid that phrase if it causes confusion. Did i say that somewhere this video?
Great video! Just one question: If the hydrogen that combines with NADP to reduce it can only come from the photolysis of water, what happens to all the other H+ ions that get pumped across the membrane? Where do they come from and where do they go?
Most of them kinda stay there help maintain that proton gradient, so that protons can keep flowing through ATP syntase so that it rotates and generates ATP. haha. Then they are pumped back into the intermembrane space again. Some of them get used in other reactions/transported else where too. E.g. Plant cells also have mitochondria! So they help there as well
Hi there, Thank you for your interest. My notes are available for purchase at www.genesisorigo.com/cambridge-a-level-biology As part of behlogy's launch on GO, both Paper 3 & Paper 5 Essential Guidelines are now available as a FREE resource for a limited time only! You just need to register on the site. After registration, you may "enrol" for the notes or resources you would like to purchase. More instructions are found at genesisorigo.com/a-level-resources-guide-to-enrollment Thanks for your support and all the best with your studies! - Ms Beh
thank you for the videos!! im having exams literally tmr and i unfortunately skipped a few of my lessons at school so i missed out on certain topics such as the sensory receptor cells 😅 very glad that my tutor told our class about your channel. truly a god send 🙏🙏
the only good thing about corona is, many talented teachers came out into the virtual world. thank you so much teacher, its really helping me with my a levels <3
@@behlogy oh gosh thats bad news coz im so bad at chem tht i dropped it for a levels but then everyone said tht i MUST have chem with bio or else bio has no value soo i am doing chem now but yeah i suck at it and donno how to get better
Hi miss, If the probability of the value calculated by X^2 is, for example, between 0.05 and 0.1. Do I write 0.05<X^2<0.1? Also, thank you for your amazing videos!!
Honestly it depends on which part of the bronchiole. If it's near thr bronchus it may have some! Further away, none. But the table is based on past papers. Generally, in a levels, it seems like their answers (esp paper1) say bronchioles have no smooth muscles
Hi i want to know that why u placed all test tubes in water bath why not one by one so is there any other condition where we separately put them in water one by one😊
Bcs it's faster to boil all for 10min together HAHA You put them in one by one when you are taking the time for the first sign of colour change. Bcs then the timing differs for each concentration.
Hi I love this video it was so helpful thanks! I have a question about Vmax and Km. On the graph it says that Km = 0.118, so why does the bottom say Km=0.07?
@@behlogy Thanks for responding❤. I don't think I misread because u said that Km on a reciprocal graph is at 1/v=0, which is at -13.4 on the x axis in the example. Then u said that km= 1/13.4=0.118 which I don't understand because 1/13.4 =0.07? If u have time please could u explain this. Thanks again.
33:58, Mrs u said that glycolipid helps interacts with water, but a normal phospholipid could do the same thing as long as it has the hydrophobic head, the glyco- group really just doesn't help in interaction with water (i think
You mean *hydrophilic head of phospholipid. Yes theres less glycolipid compared to phospholipids. But small things does affect overall stability still. The carbohydrate part of the glycolipid does help by interacting with water. Also, you will find, in general, that multiple things can do the same thing in cells/bodies. We are just made thay way :)
Mrs does Enzyme and Enzyme-substrate complex being considered as two different stuffs in the reaction? I mean if they do then the conc. of enzyme shouldn't be constant throughout the reaction cuz some enzymes are bound to substrate so i though there must be a change in conc. of enzyme
So basically what i'm askin is that does the enzyme be considered as a diiferent specie once it is bound to a substrate, or it is stilled considered the enzyme regardless of its action?
It's kinda still considered as part of the enzyme concentration bcs the enzyme part doesnt change much in the ES complex. However, the substrate does undergo chemical changes. So subtrate concentration will decrease with time. Enzyme concentration remains constant
Currently not actively making videos bcs my health isnt great and my job is overwhelming so i have zero energy remaining aaaaaah but past paper videos are on my mind!
Hi there, Thank you for your interest. My notes are available for purchase at www.genesisorigo.com/cambridge-a-level-biology As part of behlogy's launch on GO, both Paper 3 & Paper 5 Essential Guidelines are now available as a FREE resource for a limited time only! You just need to register on the site. After registration, you may "enrol" for the notes or resources you would like to purchase. More instructions are found at genesisorigo.com/a-level-resources-guide-to-enrollment Thanks for your support and all the best with your studies! - Ms Beh
I know this is quite late but I have a question; during the production and secretion of protein, the protein content is secreted out of the vesicle through exocytosis. At 25:12 when you were explaining how a white blood cell digests a bacterium cell, the soluble debris is also excreted out thru exocytosis. So, my question is this: are the substances secreted thru exocytosis always protein or can they be different substances?
