Inquiry path steps by EUN Partnership aisbl

Agnieszka - Poland

2018-03-13 16:35:44 UTC

My path is: the dependence of the activity of microorganisms on the availability of water (the amount of active water). This allows you to understand why cakes in warm countries literally float in glucose-fructose syrup;)

Marjeta, Slovenia

marjeta_decman — 2018-03-13 16:59:16 UTC

My investigation path:
In my experiment I introduced one variable (sugar content in different concentration).
I did´t have control tubes for presence or absence of yeast. I had only one control tube which had yeast suspension with no sugar.
With my experiment I saw that all balloons did´t inflate in the same way - low and medium sugar level promoted yeast activity, at high sugar levels yeast activity was inhibited. With my experiment I can prove that the sugar content has an influence on yeast activity.

Macarena Spain

2018-03-13 18:45:26 UTC

We usually do this activity at 4 th level to study fermentation.We follow a simple procedure.We use test tubes and small balloons.We ser only one control tube with tap water and 5 experimental tubes with an increasing concentration on sugar and we pour on each tube 5g of fresh yeast.Apart from studying the process and analysing the results I use this activity to learn my students how we could do it more precise by improving the experiment.

Nicola, Malta

nixy_port — 2018-03-13 20:58:06 UTC

I followed a simple yet accurate method ensuring that all set ups were identical except for the sugar content between each test tube.I failed to set up a control for every single sugar concentration however as I took it for granted that no gas will be given off if yeast was not present. My results did match the results achieved above however I only prepared four set ups. My inquiry path was most definitely a linear one.

Maria, Italy

ladymary — 2018-03-13 21:57:55 UTC

I have miss the control tube for all experiment .
i prepare the solution in the same way but when I decide the sugar preparation I didn't considerate the % of sugar in the jam!

Marta, Spain

2018-03-14 12:37:35 UTC

My experiment wasn´t so well prepared and protocolized as in the video, of course. And I did not use so many options. But I did use a control tube. The conclusions support my hiphoteses. I liked the way of work the video shows.

Francesco Piccolo/Italy

2018-03-14 14:08:06 UTC

I believe that my investigation path was acceptable even though I used few samples and mishandled the quantity of yeasts; I should have used 2g of yeast instead of 7g and at least another pair of samples with a higher sugar concentration (50g / 100g). However I am satisfied with the result.

Silvia, Spain

2018-03-14 16:50:42 UTC

I took into account the control of the experiment and controlled variables. But I think I should have replicated each concentration tube at least to times and observe the results after 1.30 and 2 hours. I didn’t observe yeast’s cells under the microscope. Ah! I used sucrose powder instead of syrup. I’d say that my final conclusion was satisfactory.

Mitko, Macedonia

miticko — 2018-03-14 16:52:16 UTC

I designed the experiment following some steps of a proposed protocol, obtaining some of the variables. Hence I didn't use test tubes for every concentration of sugar. I only use one control tube with water and yeast. I didn't take into account different time periods.
I think my final result has proven the hypothesis

Michael, Ireland

collabscience — 2018-03-14 16:55:41 UTC

My control was a test tube without sugar. It showed that yeast could not respire without a food source I varied only one feature - sugar content as g/ml. - I would use a % (W/V) in future.

I kept temperature and yeast content fixed in each test tube. I later measured the diameter of each balloon as follows.

PaolaCB, Italy

paolacannadabartoli — 2018-03-14 18:26:25 UTC

In my investigation path positive and negative controls were included, but I missed preparing a tube with no yeast (to tell the truth I had thought about that, but then I decided it might be useless, as we already Know that yeasts use alcoholic fermentation).
It would have been a great idea to replicate the sugar concentration of the 2 marmelades!
I stopped the experiment too early, I should have waited some more time (in Italian school we usually have just 50-55 min available for the lesson)
Even though the observations of the results were just qualitative, not quantitative, I think the results proved the hypothesis.
If I had to repeat the experiment, I would dilute more the sucrose solution.

Alex. Austria

2018-03-14 19:52:13 UTC

I realized, that too much sugar is inhibiting the process, but couldn`t think of the answer, that the sugar is dehydrating - so that was a really nice aaaahhh moment for me in the explanation

Andrea Checchetti

2018-03-14 20:24:43 UTC

My protocol demonstrates the effect that sugar has on yeast cell activity. Certainly the protocol followed in the video shows quantitatively at what concentrations of sugar the activity of the cells is inhibited, this allows to justify the difference between the two fruit preparations

Ana, Spain

anamarialorentegarcia — 2018-03-14 20:30:04 UTC

In my experiment I only take into account one variable, concentration of sugar and the amount of gas generated. So I evidenced that more sugar more gas, because the activity of the yeast.

I toke two bottle:

-1. Youst + Water and sugar

-2. Youst + water

I could see how the balloon in the bottle 1was more inflated

I made several mistakes:

- I didn’t take any control bottle.

- I didn’t take into account some important variables (quantity of water, sugar)

My conclusion was very simple

Alice, Italy

severi_alice — 2018-03-14 20:46:19 UTC

My investigation path is the effect of temperature on yeast activity. The concentration of sugar is the same. I haven't taken into consideration the effect of quantity of sugar on fermentation.

Aleksandra Blazevska

prof_acka — 2018-03-14 22:46:01 UTC

I was followed my fair test protocol were I was changing one variable . ( concentration of sugar ). I noticed that how concentration is increasing activity of yeast decrease. Actually at concentration of of 50% there is no activity of yeast noticed. And I don`t have explanation why is doing like that. Probably I need to go more deeper and to try another hypotheses

Jane, Bulgaria

janeraikova — 2018-03-15 13:17:26 UTC

The research shown in the movie is scientifically done. A protocol is used and the variables are determined - in our case, the presence of yeast and content of sugar. Working with control groups ensures credibility of the result. Quantitative comparisons are also made. Accurately determine the amount of sugar and water. The attempts are numbered and regularity is sought. A comparison of the numerical data from the labels of the two jars is made.
Unfortunately, the experience I made was rather qualitative to show that yeast leads to gas release.

Palma from Spain

2018-03-15 20:24:56 UTC

In my experiment only variable has been the quantity of sugar.
I have observed it for eight hours and I have observed that depending on the amount of sugar the balloon has been inflated sooner or later, except the one that’s does not have sugar that has not been Inflated

Chiara G Italy

chiara_garulli — 2018-03-15 21:03:46 UTC

Only sugar concentration change in each sample.
The negative control contains no sugar but the same amount of yeast.

I observe the samples for 4 hours.

Using ballons I determine qualitatively the effect of sugar concentration on yeast metabolism.

Performing the same experiment with special tube I try to obtain the quantitative data measuring produced carbon dioxide volume.

Pilar, Spain

2018-03-15 21:48:29 UTC

Actually my experiment only shows the yeast activity in a medium with sugar. I must to explain in detail a new protocol to demonstrate the true hypothesis.

Sophie, Austria

2018-03-16 00:17:25 UTC

A control tube was used in my experiment which did not contain any sugar. I used the concentration of sugar as variable to figure out how it affects the gas production during the fermentation. This experiment shows, that it makes a difference, when more or less sugar is added to the yeast suspension.

Next time I would use more examples with higher concentrations of sugar. I am curious at which sugar concentration the fermentation (and thus the gas production) stops.

Poonam, India

2018-03-16 06:42:44 UTC

In my experiment only variable quantity of sugar has been observed.
I have observed it for two hours and I have observed that depending on the amount of sugar the balloon has been inflated sooner or later.

munir ghanem, israel

ghmunir29 — 2018-03-16 12:16:00 UTC

one variable was tested in my experiment - sucrose consentration compaired to control tube- yeast and water only .time scaling consist of taking picture after 10,20,30 and 40 minutes.the inflated baloon due to gas emition-aftivity of yeast cells.

Nina, Slovenia

2018-03-16 13:31:24 UTC

The content of the yeast was the same and I increase the sugar content.
The results after 5 minutes:

A 1 g of baking powder + 0,5 g sugar and 5 ml of Mineral Water

B 1 g of baking powder + 1 g sugar and 5 ml of Mineral Water

C 1 g of baking powder + 1,5 g sugar and 5 ml of Mineral Water

D 1 g of baking powder + 2 g sugar and 5 ml of Mineral Water.
A lot of sugar inhibits fermentation that is in B, C and

Tina, Austria

2018-03-16 16:37:11 UTC

In my experiment every tube contained the same amount of yeast. Sugar proportion was variable in four samples and totally missing in my control tube. I also had a look at the water temperature to ensure same conditions. I noticed that the amount of sugar influences the activity of the yeast cells and the gas production.
Due to using quite a large balloon, my experiment took two hours, to be able to see any differences. I would use a smaller balloon next time to accelerate the reaction.

Voinea-Axinte Costica

2018-03-16 18:32:10 UTC

Experiment: water - yeast - sugar
Curiously it was that the balloon 2 was the one who reacted the fastest. At the end of the experiment, balloons 2, 3 and 4 had about the same volume of gas removed

Elena, Italy

2018-03-16 18:51:15 UTC

I experimented only increasing sugar concentrations to prove the hypothesis. I didn't considerate the inhibition of high sugar concentrations on yeast's activity.

Măndița Baias

baiasmandita — 2018-03-16 20:18:50 UTC

My experiment has shown that yeast is more active when sugar content is higher. I also changed the water temperature I added and I noticed that in hot water the yeast is activated faster

Ayşegül/Turkey

aysegulmer — 2018-03-16 20:37:56 UTC

Tube 1: 50 ml mineral water+5 g yeast+none sugar
Tube 2:50 ml mineral water+ 5 g yeast+10 g sugar
Tube 3: 50 ml mineral water+ 5 g yeast+20 g sugar
tube 4:50 ml mineral water+ 5 g yeast+30 g sugar
I experimented only increasing sugar concentrations to prove the hypothesis.A lot of sugar inhibits fermentation.

Helen Mihalatou

helensefer — 2018-03-16 21:42:08 UTC

The investigation path I followed concerned the effect of different sugar contents in yeast activity. So, the control that I used contained a yeast suspension with no sugar added. So, I did´t have control tubes for presence or absence of yeast for each sugar concentration.

The results show that sugar addition influences the activity of the yeast cells and accordingly the gas production. However, the balloons did´t inflate in the same way. At high sugar levels yeast activity was nearly inhibited. With my experiment I can prove that the sugar content has an influence on yeast activity. High concentration of sugar, like the one we saw in Fig Jam, seems to slow down yeast activity.

Milijana, Sebia

2018-03-16 21:58:09 UTC

The balloon reacted quickly, in which I added the most yeast and sugar. In other balloons the yeast concentration was the same, but there was a different concentration of sugar, so the fermentation process was also dependent on the sugar concentration.

Doinita B., Romania

2018-03-16 22:51:52 UTC

My experiment tracked the influence of sugar content on the amount of gas released by the same amount of yeast and water. I have found that a higher amount of sugar generates more gas.

I will repeat the experiment with a very large amount of sugar that I think will inhibit yeast activity.

Daria, Poland

2018-03-17 12:11:58 UTC

In my experiment, I tried to find the answer to the question: how and whether the amount of sugar affects the activity of yeast, the amount of gas released.
In my experiment the variable factor was the amount of sugar. In each sample there was the same amount of water (5 ml) and yeast (1 g). In the first sample (reference) there was no sugar, in the second there was 1 g, in the third - 2 g, in the fourth - 3 g and in the fifth - 4 g. I took photos in ten - minute intervals.

Vesna, Slovenia

2018-03-17 14:35:39 UTC

In the experiment the amount of yeast and water was the same in all test tubes and the amount of sugar was different. This implyes that the activity of yeast depends on the amount of sugar. According to the results, yeast needs some sugar to emmit gas, but too much sugar inhibits the reaction.

Dario, it

pd_dario — 2018-03-17 15:29:06 UTC

In my experiment was tested only the effect of amount of sugar on the gas production in qualitative mode. I did a mix of water and yeast and then splitted in to tubes to reduce error. Unfortunatley I dont had more tubes to set on the control without sugar (gasp!).

Klara, Vienna

2018-03-17 18:02:36 UTC

In my Experiment you can see that yeast needs sugar to grow but if there is too much sugar the yeast can't grow. I put warm water in my bottles and I think this helped the yeast to grow fast.

IvanaN

nenadic_ivana007 — 2018-03-17 20:03:10 UTC

I only differentiated the amount of sugar but did not add the control tubes

Sonja, Croatia

sonja_pospisil77 — 2018-03-17 21:25:00 UTC

With my experiment I was trying to find out wich ammount of sugar will effect the activity yeast cell which will be shown in quantity of gas they produce in certain period of time. The results were expected. The control tube had no sugar. I did not calculate the sugar concentration. Next time I will.

2018-03-17 22:10:33 UTC

My protocol was not considering the following characteristics:
1 total volume of samples (I had samples with different final volume)
2 I didn't make the control with no yeast.
The protocol you suggested is very clear and far more rigorous. I'll take into account for my own experiments. Thnsk

Barbara, Poland

2018-03-17 23:31:56 UTC

My experiment:
1. Testing
- Dependent variable: the amount of CO2 emitted - the size of the balloon, diameter
- Independent variable: the number of teaspoons of sugar - the concentration of the sugar solution
- Control variable: the amount of yeast - 1 teaspoon
I took photos every hour.
2. Unfortunately, I split the research and test samples at the time (I only had 4 balloons). I did not specify the sugar concentration.
3. My inquiry path was linear.

Jana, CZ

jjilkova — 2018-03-18 00:26:42 UTC

My expriment:
2 samples + 1 control tested
I was trying to find out whether the yeast plus suggar produces more gas and inflates the ballon.
The control tube showed that it did not produce enough gas to inflate the ballon.
Small ballons were used for T1 and T2 and inflated about the same.
Interpretation: Yeast + suggar produce gas which inflates the ballons. The quantity of suggar did not make a difference in the amount of the gas because the yeast cells could not use more of it or the material of the ballons did not allow to show the differences.
To find out will need another experiment.

Gilda/Italy

2018-03-18 11:35:04 UTC

The investigation path I followed is this one:

I wanted to demostrate yeast’s activity depend upon the quantity of sugar.

I used three test tubes.

In each one I put 15 mL of water and 2 g of yeast.

The tube 1, without sugar, is the control, while in the tube 2 I put 2 g of sugar and in the tube 3 I put 4 g of sugar.

I observed the three tubes after:
1. half an hour
2. one hour
3. two hour
4. four hour

After half an hour the ballon on the tube 3 inflated.
After one hour the ballon on the tube 2 inflated.
After four hours the balloon on the tube 1 didn’t inflated.
Conclusion: the quantity of sugar influence yeast’s activity. Yeast cells are more active if there is more sugar.

I believed that my protocol was linear but after I saw your video I understood that it was necessary to use other tubes with more quantity of sugar ( for example tube 4 with 6 g of sugar, tube 5 with 8 g of sugar,…..) so to observ yeast’s activity in these situation.

Aleksandra, PL

kwiekola — 2018-03-18 11:43:30 UTC

In my experiment, I wanted to show that the amount of sugar can start or stop the reaction. Small amount of sugar can start the reaction - the yeast could grow, but the big amount of sugar had stopped the reaction - yeast didn't grow.

I wanted to show, that the amount of sugar in a medium is the key to the solution. So I took the same amount of water and yeast, but an unequal amount of sugar in my five tubes. The experiment shows that the reactions depend on the amount of sugar. I didn’t make control tubes without yeast to proof the hypothesis. I would do it better in the future.

2018-03-18 12:13:10 UTC

Ayşe ARSLAN, Turkey

aysekaraul — 2018-03-18 14:57:07 UTC

In my experiment I saw that useing big amount of sugar was slowed of grow of yeast.
According to this result I can make a generalization about the hypothesis.

Bożena Poland

2018-03-18 15:12:14 UTC

I was able to comparre how the incresing concentration of sugar influences the production of gas. I have unfortunatelly forgotten about the control test.

Eduardo, Spain

nozal_eduardo — 2018-03-18 17:44:33 UTC

I tried to use the scientific method (hypothesis, experiment, analysis).
The protocol I used was much simpler than the one in the video. As a result, I did not find the point of concentration in which the activity declines. I did find that the concentration of sugar takes a part in the process.

Izabela, Poland

2018-03-18 18:24:07 UTC

I show that without sugar yeast are inactiv. I think that the hypotesis is true. The content of sugar is important. In tube with sugar there was activity of yeast. I didn't show that big amount of sugar makes yeast inactiv.

Zvonko, Serbia

gzvonko62 — 2018-03-18 19:15:03 UTC

The balloon has reacted more quickly which had the most yeast and sugar. In other balloons, fermentation depends on sugar concentration.

Natalia Grushko, Ukraine

grushko_nat — 2018-03-18 20:01:48 UTC

Yeasts are living organisms that feed on sugar. Having processed sugar, they secrete bubbles of carbon dioxide, so the ball was inflated. In the heat process is faster.

iwona_plusa — 2018-03-18 20:15:19 UTC

Klara,Austria

2018-03-19 07:54:46 UTC

In my experiment, the amount of water and yeast in each bottle was the same. The amount of sugar was different and so I could see that the amount of sugar has an effect on the activity of yeast and produces different amounts of gas.

Rishu,India

2018-03-19 13:43:32 UTC

My experiment demonstrates that high sugar content inhibits yeast activity.

Špela, Slovenia

rozman_spela — 2018-03-19 14:18:02 UTC

The experiment confirmed the hypothesis. Yeast cells need sugar for their activity but to much sugar prevents that same activity.

To fasten the activity I could have used warmer water, but I did not want to - the jam was not heated and it spoiled anyway. It would be interesting to research the temperature effect on yeast cells but I assume the experiment would not be that simple to perform.

Soni.Albania

2018-03-19 14:36:32 UTC

The result of the experiment showed out that the yeast cells need sugar for their activity,but to a certain extend,because otherwise it prevents their activity

LuciaItaly

2018-03-19 14:40:36 UTC

The balloon inflates due to the formation of a gas produced by the yeast through fermentation. To ferment the yeast it needs sugar.
[The gas that inflates the balloon is carbon dioxide]

Ausra, Lithuania

2018-03-19 16:05:49 UTC

The experiment show how sugar concentration affect activity of yeast.

Renat, Croatia

renata_pintar — 2018-03-19 17:19:13 UTC

the experiment confirmed my hypothesis. Added sugar preserves food.

Héctor,Spain

2018-03-19 17:37:53 UTC

the experiment just half confirmed my hypothesis. Added sugar preserves food, but it is not correct the afirmation that the mor sugar concentration, the more yeast activity.
In my experiment I did not prepare as hight concentration of sugar as it is shown in the video.

Pinelopi, Greece

2018-03-19 18:03:08 UTC

In the experiment, I changed only one parameter, because I was examining the correlation between the amount of sugar and the gas produced. However, I did not find out that excess sugar inhibits yeast's activity

Michelle, Ireland

2018-03-19 19:05:41 UTC

I should have had more concentrations of sugar above 40%, to show the inhibition of yeast by their food source.

Svetlana, Serbia

svetlananj — 2018-03-20 00:08:31 UTC

During observation I notice:
The balloon on the bowl with 1/3 of a spoon of sugar first begins to fill
The reaction in the vessel to 1/2 and 1 teaspoon of sugar begins much later
It reacts faster in a bowl of less sugar
After a few hours there is no change
After 6 hours, the balloon on the second bowl begins to empty, the contents are lowered back into the bowl
Conclusion:

Sugar encourages reaction
sugar content affects the speed of reaction
my inquiry path did not linear
bowl without sugar does not emit gas (even after 12 hours)

Video: https://www.youtube.com/watch?v=sb3lbX73648&feature=youtu.be

Anca, Romania

2018-03-20 06:17:07 UTC

The experiment confirmed the initial hypothesis . More sugar preserves the food better than less sugar.

Mustafa BOZOĞLAN, Turkey

mdbozoglan — 2018-03-20 08:20:55 UTC

I used the sequential technique in the scientific research method. It could also be added to the process in a sugar-free environment. the beginning of gas formation in the bubbles indicates a significant relationship between yeast and sugar content. but as the amount of sugar increases, the alcohol level may be increased. so the bacteria produced by the bacteria did not turn out to be methane. Similar results and comments have been made with friends who made other participant commentaries. the query path is expected to be linear. but some ambient conditions can cause problems with temperature and pressure. risk of contamination or chemical cleaning and hygiene effects on the container used.

Dimitris,GReece

2018-03-20 09:46:47 UTC

I did only half the way with towards my hypothesis. I have also to test temperature influence.

Rosy,Italy

2018-03-20 09:50:38 UTC

My way to operate is by using the scientific method. I try to write the observation step by step in other to make my students reflect about what was happening.

Marija,

2018-03-20 10:45:59 UTC

In experiment, I used a scientific approach. I made the hypothesis that the amount of gas is a pro-proportional sugar mass in the preparation. The experiment confirmed the hypothesis.

MaríaJosé, Spain

mgarcia58 — 2018-03-20 13:13:38 UTC

1.Suggestion to check the different sugar content and amount in the jams that the students have at home or supermarket.
2.Ask if they have ever seen a spoiled jam and if they have made questions about this fact.
3.Video to watch at home
4.Questions in the class
5. Scientific method and reflection making
6.Brainstorming: students reflect about what was happening.

Marina del Barco SPAIN

marina_bm6 — 2018-03-20 13:36:17 UTC

INQUIRY PATH STEPS
1. Research activity about yeast (homework).
2. Present two types of jams in class, one with more sugar than the other. It could be done with preparations that have different types of sugar (sacarose, fructose, etc.) and no sugar.
3. Open them and leave them on the class for a week or two.
4. Brainstorming about what have happened (come up with a group hypothesis).
5. Lab activity similar to the one proposed.
6. Lab report with group conclusions.

The experiment confirms the hypothesis. Added sugar in a certain amount preserves food.

PS. Some groups did not get the same conclusion because they use different amounts of sugar.

Petra, Slovenia

petra_munda3 — 2018-03-20 19:12:08 UTC

We made different investigation paths in the classroom.

The groups had different water temperature, different water quality (gas/no gas), different amounts of sugar and two types of yeast (fresh and dehydrated). We had only one reference tube.

We saw that the amount of gas in the same time was not equal and in the tube with the highest % of sugar was no yeast activity.

Inquiry path was not lineal.

The path followed was having the same bottle, the same balloon and the same amount of water but different yeast portion

2018-03-20 22:16:05 UTC

Alexia, Malta

2018-03-21 08:42:56 UTC

The procedure employed in the video is more complete and complex. I opted for a simpler procedure which I would expect my 13 year old students to come up with had this investigation been presented to them.

YOLANDA M (SPAIN)

yolandamarron — 2018-03-21 10:06:23 UTC

My investigation path was wrong and really simply. I did not use enough experiment to validate the hypothesis so, my conclusion was wrong. I did not take in account:
The same final volume

Two tubes with the same concentration of the jars

Different `photos different time 0 hours, 2 hours, 4 hours, 6 hours

10 test tubes with different concentration and 10 control test tubes one per each

Values tested were concentration not mass

They calculated the final concentration of sugar of each test tube

Conclusions; saccharose amount influence in gas activity but the influence in gas production does not depend linear with the amount of sugar

Jasenka, Croatia

2018-03-21 10:45:14 UTC

I've proven that the amount of sugar increases activity of the yeast but I haven't proved what quantity of sugar inhibits yeast activity. So, I actually haven't validated my hypotesis.

2018-03-21 13:09:53 UTC

My hypothesis was correct. I wrote that adding preservatives prevents spoiling (adding sugar prevents spoiling food).

Izabela 2, Poland

2018-03-21 13:52:04 UTC

1.The condition of tubes were the same: the amount of water and yeast and temperature. The tubes differed between each other the amount of sugar and then the size of balloon /the amount of carbon dioxide/.
2. I had one control tube without sugar. I compared the size of balloons in test tubes to control tube.

3. My inquiry path was linear.

Theodor L. Greece

theo_leftheroudis — 2018-03-21 17:41:53 UTC

My course to find the answer and to confirm my initial case was not very good. I had to design it better.

What is my dependent variable?

It is the quantity of gas to be produced.

What is my independent variable?

It is the amount of sugar in the mixture with the yeast.

What else can affect my dependent variable apart from the independent one? these variables are controlled.

Amount of yeast-water mixture should be the same everywhere.

The containers have the same size.

The balloons are the same.

Placing on the pipes.

The temperature is constant and constant.

Have the blends done properly.

We place different amounts of sugary water in the yeast mix and we see balloons at regular intervals.

The delay in gas production is due to the largest amount of sugar in the yeast mix.

My route was not in a straight line but during the experiment I had to go back several times to get the right mixes.

I could choose another approach path to put plain sugar or glucose or brown sugar or fructose. I could approach it from many angles.

Ceban Ana, Moldova

canisoara — 2018-03-21 17:48:02 UTC

More sugar preserves the food better than less sugar.Demonstrates that high sugar content inhibits yeast activity

Zdena, Czech Republic

2018-03-21 17:48:45 UTC

I suspected that presence of sugar might be the key, which was correct, unfortunately I was not patient enough. I should have mve observed it all a bit longer, took more pics and make let´s say a graph from my results. Also I tried to add lemon juice to one of my mixtures, unformtunately

Nataša, Slovenia

koprivnikarn — 2018-03-21 20:35:14 UTC

I planned a controlled experiment, with dependent and independent variable. I forgot to include controlled experiment for each of the erlemayer flask with different amount of sugar (I only had one without sugar).

Noel, Malta

noel_harmsworth — 2018-03-21 21:39:49 UTC

As compared to the one presented in this video, my approach was conceptually similar but the execution was much simpler.

I was lucky that my results reflected the scientific expectations even though I did not really make an effort to relate my variables (sugar concentration) to the variables in the fruit preparations (as per the labels).

Also I only prepared one control as my aim was to confirm that yeast can only produce a gas when it has sugar that it can break down. The video on this page on the other hand is taking the approach of ensuring that sugar does not produce the gas without yeast.

Anamaria, Romania

2018-03-22 04:07:34 UTC

Not good . I take too small quantity of sugar. Next was the same.

Maria DC

mariadecarlo — 2018-03-22 10:03:42 UTC

This is the summary of the protocol with the science colleague:
1.5 g. of brewer's yeast were added to 1.8 ml of water without mixing, in each of the 5 tubes. Different amounts of sugar were added to the mixture: 1st tube 0g sugar; 2nd tube 3g sugar; 3rd test tube 6g sugar; 4th tube 9g sugar; 5th tube 12 sugar. We added a 6th tube with 1.8 ml of water and 15g of sugar, without yeast.
At each test tube we put a balloon like a hat ... The blends were left undisturbed for about an hour ....
Comments after one hour:
the balloon 2 was fully inflated, the others were deflated with excitement for the balloon 3 which was slightly swollen.
The results of the experiment mainly show that:
the sugar is necessary so that the yeast can ferment and emit carbon dioxide. In the absence of sugar (test tube 1), no gas was produced as in test tube 6 due to the absence of yeast.
Too much sugar (in tubes 4 and 5) have inhibited the activity of yeast with a low production of carbon dioxide.Conclusions:
The experiment was successful and we detected some procedural errors. We would have to peel the ingredients before inserting them into the tubes. In fact only the test tube n. 2 which was slightly misdirected gave good results.

Anna Italy

2018-03-22 10:03:50 UTC

This is the synthesis of the protocol I used, working in collaboration with my religion colleague:

1.5 g of brewer's yeast were added to 1.8 ml of water without mixing, in each of the 5 tubes. Different amounts of sugar have been added to the mixture:

Test tube 1: sugar 0 g
Test tube 2: 3 g of sugar
Test tube 3: 6 g of sugar
Test tube 4: 9 g sugar
Test tube 5: 12 g sugar
we added a sixth yeast-free test tube with 1.8 ml of water and 15 g of sugar.A balloon was attached to each tube. The blends were left undisturbed for about an hour.

Remarks: after 1 hour, the balloon 2 had completely inflated. The other balloons were deflated except for Balloon 3 which was slightly swollen.

The results of the experiment mainly show that:

1. Sugar is necessary for the yeast to ferment and release carbon dioxide (CO2). In the absence of sugar (tube 1), no gas was produced as was the absence of yeast in the tube 6.
2. Too much sugar, in tubes 4 and 5 have inhibited the quantity of yeast activity with a low production of carbon dioxide.Conclusions:
The experiment was successful but we found some procedural errors. We would have to mix the mixtures before inserting them into the tubes. In fact, only the tube 2, which was slightly mixed gave good results.

Gaia, Italy

gaialombardi69 — 2018-03-22 11:14:23 UTC

My experiment was quite similar to the example, but more "rudimentary" in materials and organization. I pointed on pupils' autonomy and group observation.

monica garcia

2018-03-22 21:33:58 UTC

my protocol was simpler but in a way quite similar, the only factor changing was the amount of sugar, and the results were basicaly the sam

my protocol was similar

a_scheuringer — 2018-03-22 22:47:05 UTC

Claudio

2018-03-23 17:36:45 UTC

My protocol was simpler than yours but very similar: the only difference was the concentration of sugar.

Kristina, Slovenia

2018-03-23 22:52:46 UTC

I have followed similar investigation path. My experiment based on different amounts of sugar content (the affect of sugar on yeast cells) and it was far more simple and faster than yours experimental approach. I have reached the same results; yeast activity (gas production is observed through the inflation of a balloon) is promoted by certain amount of sugar (inflated balloon), high amounts of sugar inhibit yeast activity (gas production is absent, the balloon remains empty).

Paulo Dionsio, Portugal

paulo_dionisio — 2018-03-24 12:17:02 UTC

The protocol of the experiment is simpler than that demonstrated in the video. The difference is in the concentration of sugar used in the fermentation process.
When more sugar is used, it is the preservation and preservation of the jams / foods, because the high sugar content inhibits the activity of the yeast so that the yeast process does not materialize.

Arnaud, France

2018-03-24 14:18:51 UTC

The changing factor in my experience was the amount of sugar in the container. However, I completed the preparation by the same amount of water in each tube (while the video presented here adjusts its complement to 30 ml to have the same total amount)

Michela, Italy

michelapellizzari4 — 2018-03-24 14:29:35 UTC

I followed a circular investigation path to reach an answer: I tried alone, I discovered my hypothesis with my daughter, we experimented these. I compared my experiments with student’s experiments. I tried again with more attention to the quantities of sugar and yeast. I tacked photos to document it. I compared my experiments with the video posted and I understood that I haven’t find the % of sucrose in water that inhibits gas production and I haven’t found the ml of gas produced. I want to try again and to find the answers to my questions.

Lina, Lithuania

step_lina — 2018-03-24 15:39:43 UTC

The experiment confirmed my hypothesis. My protocol was simpler then in video.

Reneta Raicheva. Bulgaria

2018-03-24 18:54:54 UTC

The inquiry path is similar, thxx! :)

Grazyna, Poland

sp171wesola — 2018-03-25 21:16:21 UTC

I think I should have had control tube or cup and pay more attention to the amount of sugar used for experiment. Maybe I never reacher the minimum to start the yeast work

Fiona

2018-03-26 15:11:39 UTC

I did not include a control experiment to verify my results. This was an error on my part.

sunce

suncezgb8 — 2018-03-26 15:25:42 UTC

I use less samples but protocol was the same.

Carlo italy

carlogino — 2018-03-26 18:54:27 UTC

I used a simple experiment
but in the end you can connect with yours, the only difference was the concentration of sugar.

Jason, Ireland

JasonComerford — 2018-03-26 19:57:43 UTC

I used a similar protocol, however mine was less elaborate. We differed in the use of the control (i was taking the "syrup doesn't spontaneously emit gas" as given, but can appreciate that my students might not). I used less test samples due to the constraints on my time in the lab.

Cecília Pereira, Portugal

ceciliadpaiva — 2018-03-26 20:18:24 UTC

The procedure employed in the video is more complete and complex. I use less samples but protocol was similar. I think that I may say, as a conclusion, that more sugar preserves the food better than less sugar and demonstrates that high sugar content inhibits yeast activity.

chemingui firas

cheminguifiras1966 — 2018-03-27 10:12:58 UTC

nabeul , Tunisia
i tried to use a similar protocol , by making constant the quatitity of yeast to 1 gramme and to vary the added sugar in the different tubes from 0 grammes to 8 grammes the results and the comclusion are summirized in the follow document ,for our case in order to avoidjam' spoil the efficient ammount of sugar should be added in order to inhibit any yeast multiplication ( i added the document in my learning diary )

Joyce India

sec_coordinator — 2018-03-27 17:16:05 UTC

Using different sugar concentration I got maximum inflation in the t

Joyce India

2018-03-27 17:42:24 UTC

After 4 hours the tube with the high concentration inflated the balloon to the maximum size. However keeping in mind the initial problem, the preparation with the higher sugar concentration was better preserved. I added a lot of sugar in another tube and put in the same amount of yeast . When observed after 4 hours there was no significant increase in the balloon size.Yes the path was linear as the conclusion of the first stage gave rise to the second stage analysis.

2018-03-27 20:02:55 UTC

The

Eugenia, Romania

2018-03-27 20:06:35 UTC

Experiment is well organized. It is certain that sugar stops yeast activity. More sugar means well-preserved product. But because it is a preserve for human consumption, is it healthy?

Kavita, India

2018-03-28 03:38:48 UTC

I used the same quantity of yeast and varied sugar content but the water added was different as I had to soak the yeast. Maybe that's how the test tube with more water showed more gas. My inquiry path was linear but didn't take in control and experimental method. I only experimented with varying quantity of sugar and water. Also, I should have waited for more time. Maybe measured at different time intervals and noted down results.

Kristina, Croatia

klucic5 — 2018-03-28 09:44:20 UTC

My protocol is very simple just observe the difference in the concentration of sugar.

Aoife, Ireland

2018-03-30 10:59:07 UTC

I used a simpler method/protocol due to constraints in the lab of equipment. I used only one control and not as many different sucrose concentrations.
The investigation confirmed the proposed hypothesis

orsola, Italy

orsola_parisi58 — 2018-03-30 11:36:16 UTC

I made use of a simpler experiment than the one used in the video and I pointed out that it is only the concentration of sugar that inhibits yeast proliferation.

Miguel Angel, Burgos (Spain)

kapy83 — 2018-03-30 16:41:25 UTC

I have used a sample only with water and I have been adding different amounts of sugar.

Anamaria, Romania

2018-04-03 06:40:39 UTC

I used a simpliest path with water and sugar.

Anna, Italy

prof_deruvo — 2018-04-03 10:10:16 UTC

I didn’t use control bottles without yeast so I couldn’t verify that the gas come from yeast activity. I consider it obvious from past experiences but it’s not obvious that without yeast we would have any gas. I ad dry yeast because easy to misure a same quantity (it was ready), so in the concentrated samples yeast mainly stayed dry. I didn’ t compare the concentration of sugar with the initial labels so even if I arrive to similar conclusion in general I couldn’t be sure about our particular case of study. That’s could be done even as a esteem and importante for the students to understand the role of measuring in lab. work.

Slavica, Croatia

ps_slavica — 2018-04-03 18:13:27 UTC

Just watch different size of baloons and thinking about results.

Bertha, México

chem_ur_v17 — 2018-04-03 19:54:48 UTC

I could see that the higher concentration of sugar, the greater the amount of gas. At different temperatures, gas production was faster at 40 ° C. At 2 ° C the activity of the yeast is inhibited, there was very little gas production.

By mistake, I added a double amount of water to the tube at 40 ° C with a higher concentration of sugar and even then the largest amount of gas was generated.

The last observation was at 6 hours after the experiment started and there was no more gas production. The production was during the first hour. I think the investigation path is linear. There are new questions to explore.

Kathryn, Armenia

quickstepintomyheart — 2018-04-04 06:42:02 UTC

I like Bertha's idea about temperature. If nothing else I think it would be something to consider in your controls. Typically we ask our students to do a 5 by 5 type of analysis. This means 5 samples for each of 5 different conditions. This helps incase there is something amiss in one of the samples. So looking at the experiment that they have in the video (I was unable to do the experiment myself due to supply issues) I would then repeat the experiment with the yeast and sugar 4 more times for each of the concentrations. For the ones where there was no gas production I would repeat only the first two concentrations and not repeat the others mostly to conserve resources.

Semih, Turkey

2018-04-04 21:19:59 UTC

My path is conceptually close to the one on the video but much simpler. I compare the gas production in different ampunts of sugar levels. The amount of yeast and water are the same , the temperature is stable so the only focused point is the effect of the sugar quantity

Nițescu Emilia-Elisabeta, Romania

2018-04-05 07:31:15 UTC

My conclusion was close to the one in the video but it was simple and not detailed.
Just looking at the two jars at first, we see that they are the same but then the ingredients content shows true value.

Ricardo RG: I get impressed by your investigation, I did not do measure of among of yeast, water and sugar, and I could not compare results with more accuracy. I have seen other investigation of classmates have done similar studies, they are great students and researchers, even have used different temperatures for their test tubes as you had. I think some classmates have many knowledge of chemistry.My balloons expanded more and more sugar it had, but I did not compare different situations of among of ingredients, and temperatures. I did not do a good protocole.

RicardoRG — 2018-04-06 19:23:58 UTC

Loved the investigation done. Will definitely do it with my students in lab. It would be really fun to do it and a highly enriching experience.

2018-04-08 15:32:33 UTC

Salima India

2018-04-09 15:49:13 UTC

I took three tubes.
I assured that the volume of yeast was constant in all three tubes. Also the volume of water in all three tubes varied according to the sugar concentration
My experiment was more or less on the same lines but did not have so much precision as there were not many readings taken as shown in the video. However I did use a control where no yeast was used at all.

Majid - Pakistan

2018-04-09 16:05:06 UTC

The investigation path was similar to what is demonstrated in the video but not as elaborated, which goes to show that the same conclusion can be drawn with a simpler experiment design.

Crina, Romania

ecrinaaurelia — 2018-04-09 16:45:28 UTC

I only differentiated the amount of sugar but did not add the control tubes

Serena, Italy

serena_dorigotti — 2018-04-13 11:42:54 UTC

I followed a similar investigation path, but I prepared only five tests. I thought that it was sufficient.
I changed my hypotheses from second step, because my first hypothesis was wrong (I thought that the difference among two fruit preparations was the content of preservatives).

Sarah, USA

sab205 — 2018-04-14 17:21:33 UTC

I set-up my experiment similar to that of the protocol with one significant difference. I tested the variable of sugar (content) rather than yeast. My control balloon had yeast, but no sugar. In the protocol, the control balloon had sugar, but not yeast. My results were similar to the protocol. However, one observation that I was unable to account for was the lack of reaction in Balloon 1 (the control- yeast, but no sugar). If I am understanding the chemical reactions of yeast and yeast combined with sugar, then my control balloon should have produced some gas since it contained the yeast. Since the protocol did not have a sample with yeast and no sugar I was unable to confirm this observation. Did anyone have a control with yeast and no sugar that can comment on the reaction (or lack there of)? THANKS!

Mirela-Emilia Pop, Romania

mirelaemiliapop — 2018-04-15 04:23:48 UTC

The investigation path was similar to what is demonstrated in the video but not as elaborated, which goes to show that the same conclusion can be drawn with a simpler experiment design.

Ourania Lampou Greece

2018-04-15 11:10:31 UTC

I used the same bottle and the same amount of water but I increased the amount of sugar.

Audrey Dublin

a_carty1 — 2018-04-15 12:29:02 UTC

Yes, more sugar gives rise to more gas

Ozrenka, Croatia

2018-04-15 13:58:20 UTC

I used only 6 test tubes (0%, 20%, 40%, 60%, 80% and 100% syrup) and I placed them on room temperature (22*C). The amounth of yeast was same in all test tubes. Investigation path was similar to the one demonstrated in the video. The only controle tube was the one with 0% of syrup. Results were pretty much the same.

zeynep , Turkey,I followed the same protocole with exception of adding more sugar

2018-04-16 13:26:52 UTC

Jeane de Fatima, Rio de Janeiro - Brasil

jeanedefatima — 2018-04-17 13:28:14 UTC

excellent experiment we can see that the reactions differ because of the amount of sugar I am impressed imagine a child perceive through this.

Alexandra , Romania

2018-04-18 17:52:00 UTC

I only ysed water and sugar. same results, even if in a simpler manner.

Samet Yavuz TERZİ , TURKEY

2018-04-19 07:54:12 UTC

The simplest is water and sugar

cihan süle

cihansulebilsem — 2018-04-22 02:57:59 UTC

My hypothesis was wrong and than I followed the similar way as in video demonstrated in the video. The result was successful.

Nurhayat Kayar

2018-04-23 16:17:01 UTC

I investigated path followed Scientific research Method.
Problem,observation,enformation,hypothesis,to check experiment (two variant ),result,if result is false, to hypothesis be turn back .to Result yeast produced CO2 and balloon
swells.

nazım kırdaş

2018-04-24 08:42:03 UTC

I focused on the problem first. I think about the solutions. I found the solution that I see fit. I have identified and revised the missing of the solution. and I get the result.

meryem eğrioğlu

megri_1971 — 2018-05-07 19:21:05 UTC

turkey
the amount of sugar increased in proportion to the amount of gas

Hülya Kartal

2018-12-18 20:53:45 UTC

Yes

Eylem GÜRKAN

eylemgurkan — 2019-01-27 22:16:11 UTC

çağdaş turan turkey

113aytoldu — 2019-03-21 08:13:38 UTC

ok good no problem

Δημήτρης

dkelefiotis — 2019-06-02 14:22:15 UTC

Το μονοπάτι της διερεύνησης ήταν αντίστοιχο σε μικρότερη κλίμακα με μόνο μια παράμετρο (τη συγκέντρωση της ζάχαρης). Αποτελέσματα ήταν πανομοιότυπα.
Το μονοπάτι ήταν γραμμικό με σκαμπανεβάσματα (αλλαγή θερμοκρασίας επώασης).

Ivica G

ivica_gregurec — 2019-09-09 20:18:48 UTC

Ivica G.

ivica_gregurec — 2019-09-09 20:18:49 UTC

Ok , it was good result