Osmosis in Potato Strips - Bio Lab
Vložit
- čas přidán 10. 06. 2017
- Instagram flashcards revision every weekday: / igcsebioflashcards
Osmosis is a special type of diffusion that applies to water and other solvents.
If you take a litre of pure water, and compare it to a litre of sea water, which is very salty, there is less water present in sea water litre because some of that litre is occupied by salt. The saltwater has a lower water potential.
If there is a partially permeable membrane, like a cell membrane, separating two different samples of water, there will be a net movement of water from the place with higher water potential to the place with lower water potential.
This is the reason plant roots take in water: the rain water the enters the soil has a higher water potential than inside of the roots, so water moves into the roots by osmosis.
We can demonstrate this in a lab setting using potatoes.
First you’ll need a cork borer to get your potato strips. Push it through the potato, then use the narrower piece to push the strip out.
For this experiment we need 18 strips. Once you’ve got as much as you need, tidy them up with a knife to remove the skins.
All strips need to be the same length to begin with. He we’re cutting them all down to 6cm.
Once they’re ready, get 6 beakers and put 3 tubes in each. This will give you three repeats for each solution.
Next thing to do is make your solutions. Put a sheet of paper on the balance, hit “tare” to get starting point of zero, and add the salt until it reads “1g”.
Once that’s in the beaker, you need 100 mL of water. Pour into the measuring cylinder keeping your eyes on level with “100mL” until it reaches the line. And then add that to your salt.
Here we’ve just made a salt solution of “1 g per 100mL”. In this experiment we need six solutions: 0g per 100ml, which is just pure water, and 1 to 5 g/ 100mL in 1 g increments.
Once the solutions are ready, pour them in to immerse the potato strips.
Start the timer, and leave them for 20 minutes.
After 20 minutes your have to measure all of the strips. Measure them as accurately as possible. To the nearest mm is good for this experiment.
As you’re working with the potato strips you probably notice that the once immersed in more concentrated solutions are more soft, which the ones immersed in lower concentrations are much more turgid.
Make a quick note of each value you measure as you’re going.
To process the data you need a table of results with all concentrations listed, as well as the starting lengths of the strips. These all started at 6.0cm.
In the next column put in the values your measured, and then calculate the percentage change for each individual strip. Notice the negative sign on some values, this tells us whether the strips increased or decreased in length.
Next you can take an average of changes in length. These are the values that we need to put on a graph.
The graph should show the average change in length against the salt concentration. And the results from this experiment show a nice downward curve.
The lower salt concentrations result in an increase in length of the potato strip, meaning water has ENTERED the potato strips by osmosis. This means there is a higher water potential inside the solution compared with the potato. We have a hypotonic solution.
At higher salt concentrations, however, we have a decrease in potato strip length. This tells us the water potential is higher inside of the potatoes, so water as left the potato strips by osmosis. We can say that the solutions are hypertonic to the potatoes.
At the point the graph crosses zero, which is about 1.4 g/100mL salt, the solution is isotonic, meaning the water potential inside potato is equal to the solution, to at that point there is no net movement of water.
i learned this in 5 minutes instead of spending hours reading a whole textbook
How did he find the change in length
@@Nevey2fye he measured it...
Thank u
My teacher made me watch this lol
Would've taken a min if you read the book
The sheer quality of this video is astounding, especially considering the usual sort of videos school shows us.
Yas
Beautiful work done..I noted that too
I am BLOWN away how well this is made. Thank you Science Sauce!
I love to find this type of videos in CZcams, with a great edition and explenations!!!!
+D94 Dadu Pro Thanks, I appreciate the feedback.
Explanation you mean
hey man, a question, what tool did he use to pull out the potato strips?
Explanations * ♥️😘
I used a cork borer.
this video actually helped me with my science homework. it explains well if not basic but well, and is formatted and made very well. awesome intro showing that this isnt a boring lesson of a teacher who drones on and on about ... well ... not the topic ( i have had too many of those teachers ).
I will take anything a JoJo says with utmost respect, especially the most gentlemanly one.
JOJO FAN
is this a jojo reference?
this video was very helpful in my lab experiment. THANK YOU SO MUCH!!!!
This was a very good explanation to understand, you made it very clear now, thanks for helping me with this!
So well explained. Observations like size changes make science cool. Comparison and scientific method.
Better than my school teacher xD
hey man, a question, what tool did he use to pull out the potato strips?
@@daspapas dildo
You pakistani?
same
Haha
I came here for the experiment, and i personally love the british accent. The word "water" said so many time, just bring this video to another level ^^
Wooer
A very useful and helpful video for my gcse biology. This video is very easy to understand. Thank you very much.☺👍
Thanks for answering my research question and literally everything what I need to include in my lab report about Osmosis!!!
Hi. Would you mind sending me a copy. I'd Iike to read it
so your're an ib student
this was amazing, your explaining is exceptional
Thanks!
@@Science_Sauce Its ok!
WELL CARRIED OUT + results at the end to go with it .. TQ and will certainly be helpful for my own students 😁👍🏻👍🏻
Watched 4 videos before this one. Good job, I finally understood!!!!
This helped sooooo much. Thank you!
Why can't school teach us like this
more bette than my teacher xD
school is making me literally do this right now
Ooh Gosh, now I got it. Thanks so much bro, this video was so helpful👌
You’re very welcome
This makes sense! I'm feeling a bit more confident for my test tomorrow
This video was oddly satisfying :)
really good vid. Really good use of language and explained very well. Thanks
This a a very valuable resource. I will try it with my class!
Great video, nice work 10/10
This was outstanding so simple to understand
Thank you so much for your vedio. It's really helpful for me to plan the experiment for my student.
You’re welcome!
This video is amazingly well made, and easy to understand.
Couldn't concentrate because of your awesome accent!!😭😭🥰🥰🥰🥰🙀
Best explanation ever ! 😍😍😍😍😍❤❤❤❤❤❤❤❤❤❤❤❤❤❤❤❤❤❤❤❤❤❤👍👍👍👍
Thankkkkk yoooouuuuuuu sooooooo mmmmuuuuucchhhhhh !
Not only is this super helpful, but the music is catchy as well, lol
Thank you, very effective video
This video was helpfull for my lab thank you
where the plotted line crosses the red line, at what salt concentration (in g/ml) would a potato be placed in for it to experience no change in length?
Bro thank you for actually EXPLAINING TJE PRACTICAL INSTEAD OF JUST SAYING RANDOM SHIT AND EXPECTING 14 YEAR OLDS TO UNDERSTAND WHAT OSMOSIS IS INSTANTLY
Congrats! This video has been chosen from our school for an assignment.
Are you in djis
@@kingexcalibur7619 ye
Grade 8 what
@@kingexcalibur7619 ur grade first
Same here8🥲
I need more vids about science, I can learn more from this than school
thanks for making video . your video helped in doing my homework
same
Explains very well
Very helpful, thanks!
This is soo useful better than my science teacher
This video was superrrrrrrrr duperrrrrrrr helpful Science Sauce is the best ever
Great video, ive got a question hopefully you can find the time to give your thoughts. Your experiment ran for 20 minutes, what do you think would happen if it went on for an hour? or maybe 1 day? In the case for higher salt concentrations, do you think eventually some of the water would go back in to the potato? or would this be just a one way thing? In cooking, there is a thing called a dry brine, where you add salt to lets say a steak, and leave it outside/fridge, at first water comes out of the steak onto the salt, but after more hours that salt liquid gets reabsorbed into the meat... i realize there are different factors, but im wondering if somehow in your experiment, there would be a time when the water could be reabsorbed into the potatoes
Movement of water via osmosis will occur until the water potential is equal inside and outside of the cells. This may take 5 minutes or 20 minutes or longer. Regardless, once this balance is reached there will be no further net movement of water. I don’t know how dry brine in cooking works so I can’t comment on that as a comparison to this experiment. I hope this helps.
@@Science_Sauce thanks !!
that's one great question man
very useful information
thank you
Thanks a lot. Very helpful.
I loved this video
Very well explained and informative.
Very very helpful.... 👍
it help me so much thank you
Thanks, really helped
Bro where this video was back in 2012 when I needed it but love the video ♥️♥️👍
Thanks, great for help with planning my practical tomorrow :)
my ap bio teacher told me for better accuracy use one potato for the strips because each potato has slighty different solute concentration and somewhat differs in the solvent of water therefore using one potato theoughout the entire process may lead to better accuracy in final results! :)
How does your AP bio teacher intend to get 18 strips from a single potato?
Science Sauce oh, the way we did the lab, we used one potato per test tube for 11 tubes in total!
This video is helping me explain turkey brining on Thanksgiving
Bro this was so helpful
Why did you ensure that all the potato strips were equal in size at the start of the experiment?
cheers mate, super useful
Thank you
Excellent job thanks
What a time taken after put piece of potatoes into the beakers
Great video, but you would have shown how to calculate the percentage and average change in length
Thanks science sauce,U the real ones!
You’re very welcome. Who are the fake ones???
@@Science_Sauce the moneyhungry sites that don't teach you nothing
We are writing 5 pages of essay from a 5 minute video.amazing !
same i swear to god im making a freaking LAB REPORT
@@hilol5129 same here and I'm in secondary level education. I thought it would be easy to do an easy experiment like this but I was wrong. Not much things to talk about
ikr ugh i had to compromise and over-exaggerate my lab report
First we peel the potato we will also need 18 strips, we then needed to cut all the strips down to 6cm. Next we made our solution we needed, a sheet of paper on the balance. We had to wait tell it reached 1 gram, then we got 100 ml water to add to the salt. Then we poured the water in the beaker with the potato strips. The leave them for 20 mins after leaving them for 20 mins we had to measure them.
Thank you learned a lot 🎉😊
Thanks a bunch! ^-^
watching this coz I don't have a potato, plus it's lockdown in our area 😪
This video was very helpful. I just have a question. What is the question investigated in this experiment?
“What concentration of NaCl has an equal osmolarity to potato tuber tissue?”
God bless you thank you appreciate your efforts
Hi, what can be a negative control for this experiment?
Thank you
Wow going to write my paper 3 tomrrow
Best explainer ever
Could extend and model animal cells on macroscopic scale with slugs.
In pure water they'll swell and ultimately "explode"
If placed in salt water, they'll shrink and shrivel up.
Dude that intro I thought was that one lol peep song. Tripped me out so hard bc my chrome was on auto play them all of a sudden I hear this song:
Okay now that I listened to the intro a few times it doesn't sound like it to much but here
Lil peep angel dust
brilliant!!
how did you calculate the change in length as a percent?
Thank You!
My man chucking potatoes into water
Wildly variable results for the 3 cores in pure water ? So am I to understand that this is not a good way to get a nice salty taste in your potato ?
Sound this will help for my exam
Did you do well ??
you saved my life
Much helpful.
Is it necessary to cut in that way. . can we use any shape of potato ..?
thank you
Thank you 👌😊
How do we reverse the change?
Do we put it in water or a 1.4gm/100 ml solution
Does osmosis work with solids too? If you'd just put salt on the potatoes wouldn't it extract the moisture?
Thank you!
No. Osmosis only works when a solvent is present (in living organisms that solvent is water, but the same thing would happen with ethanol etc.) but it won’t occur without a solution. Dry salt would have no effect relating to osmosis.
Really helped me for my exam
Which concentrations result in the movement of water into the cells?
god you helped me so much
Pls for the third column aw did you arrive at change in length in percentage... I don't understand the calculations
Thank you so much!!!!!!!!!!! i love u
3:59 how. Do u get the change in length in percentage? Whats the formula? Thanks
( (final - initial) / initial ) x 100
Who else doing osmosis in quarantine for homework
Thanks science sauce for this. Very helpful
lol studying this rn same
me
How many grams of salt do I need to make a hypotonic, isotonic, and hypertonic solution? My teacher is making us do this at home and she didn’t really even teach us much. It’s an anatomy and physiology class and I think she expects us to remember stuff from biology class but that was three years ago for me so I don’t remember a single thing
How do you find the change in length and mass?
Please answer thank u
You know when a tube is filled with 20% sucrose solutions does it mean that the other 80% is water?
Yes, probably. Unfortunately using percentage to refer to concentration is a little vague.
❤😂 thank you for your support
which size cork borer did you use?
I looked this up cause mine failed and I don't wanna disappoint my teacher since she's so nice
Slighly off topic, but does this mean that if you want to marinate meat, you should NOT add salt to the marinate? = dryer meats? or is the meat like chicken, pork, beef are always has more solution?. How does "brining chicken" works?
I don’t know a lot about cooking but a marinade is a solution, containing solutes that you want absorbed (by diffusion) by the tissue of the meat. More or less salt might influence the flow of water from the marinade into the meat, but it’s the solutes (the flavourings) that you want in the meat anyway, so I doubt using less salt would influence the diffusion or the marinade ingredients.
I left the hub for this I wanna go back now