A. Title

Diffusion and Osmosis Experiment based on Solanum tuberosum . The nature of the substance and the concentration of the solution are different.

B. Objectives of the Practical Work

This practicum was conducted to observe the processes of diffusion and osmosis.

C. Tools and Materials

 

D. Work Procedures

E. Observation Results

1). Diffusion

      The steps we took were to clean 4 beakers and then fill each beaker with 50 ml of water. After that we put 1 spoon of nutrisari spatula into 1 beaker and stirred it quickly and simultaneously with the third glass. The second glass we used the same measurement, which was 1 spoon of nutrisari spatula too, but in this second glass we did it without stirring like in the previous glass which was stirred. Then in the third glass, we put in 10 drops of food coloring using a dropper by stirring quickly and simultaneously with the beaker containing nutrisari which would also be stirred. In the fourth glass, we put in 10 drops of food coloring using a dropper without stirring. Then don't forget we also calculate the time using a stopwatch needed by the two solutions to mix with the solvent and we can find out the results of the experiment we did.

     Based on the results of observations on the diffusion process with the Nutrisari sample experiment as a substitute for CuSO4 Crystal material _and food coloring as a substitute for Eosin Solution material. A time difference was obtained in the stirred sample and the unstirred sample.

- Unstirred Nutrisari sample

- Stirred Nutrisari sample

- Unstirred food coloring

- Stir in food coloring

2). Osmosis

      In osmosis we use Solanum tuberosum tuber as a sample and then we measure it. After measuring it, we cut the potatoes into 2 equal parts. then we clean and dry both potatoes with tissue, and weigh them and calculate the weight of the potatoes. After going through the weighing process, we prepare a beaker glass and fill each beaker glass with distilled water and 50% NaCl solution as much as 50 ml. Continued by inserting the potatoes that have been weighed into distilled water and 50% NaCl solution simultaneously. Let the potatoes sit for 60 minutes.

- The process of soaking potatoes in NaCl and Aquades solution

- Potato weighing process

F. Discussion Results

Pada tanggal 25 september 2024, kami kelompok 5 telah melakukan pengamatan pada proses difusi dan osmosis. Pada proses difusi, kami menggunakan sampel nutrisari sebagai bahan pengganti Kristal CuSO₄ dan pewarna makanan sebagai pengganti  Larutan Eosin. Kemudian pada proses Osmosis, kami menggunakan tuber  Solanum tuberosum sebagai sampel kami. Praktikum ini diawali dengan menyiapkan segala alat dan bahan yang  sudah dipesan oleh asisten lab. Adapun alat dan bahan yang telah kami persiapkan  adalah pewarna makanan, nutrisari dan kentang. Untuk bahan lainnya telah  disediakan didalam laboratorium. Diawali dengan pengamatan pada proses osmosis. Pada osmosis kami  menggunakan tuber Solanum tuberosum sebagai sampel. Kemudian ada Larutan  NaCl 50% sebagai pelarut, aquades juga sebagai bahan yang penting dalam  pengamatan ini. Alat yang kami gunakan ada pelubang kentang, alat ini berguna  untuk mengambil tuber dari Solanum tuberosum dengan ukuran yang sama.  Langkah awal yang kami lakukan adalah melubangi kentang dan mengukur  kentang menggunakan mistar, dengan ukuran 2 cm. Setelah mengukurnya, kami  memotong kentang mejadi 2 bagian yang sama. kemudian kedua kentang tersebut  kami bersihkan dan keringkan dengan tisu, dan menimbangnya dan menghitung  berat dari kentang tersebut.

      - Setelah melalui proses penimbangan, kami mempersiapkan gelas beaker  dan mengisi masing-masing gelas beaker dengan aquades dan larutan NaCl 50%  sebanyak 50 ml. Dilanjutkan dengan memasukkan kentang yang sudah ditimbang  tadi kedalam aquades dan larutan NaCl 50% secara bersamaan. Diamkan kentang  tersebut selama 60 menit. Kami mengamati apa yang terjadi pada kentang tersebut, yang mana pada gelas beaker yang berisi larutan NaCl 50% lama kelamaan kentang tersebut mengecil dan yang awalnya mengapung diatas lama kelamaan mulai turun  kebawah. Kentang yang awalnya dengan panjang 2 cm dan berat 1,1916 gr  berubah menjadi 1,8 cm dan berat 0,8421 gr. Pada larutan NaCl 50% sel-sel kentang mengalami kekurangan air akibatnya kentang menjadi plasmolisis. Kondisi ini mengakibatkan tekanan turgor. Akibatnya, kentang menjadi lebih  empuk dan lembek. Sedangkan penurunan berat kentang terjadi akibat  perpindahan air dari sel-sel kentang kelarutan. Maka dari penjelasan dan  pengamatan kami, kami mendapatkan hasil hipertonik (plasmolisis).

      - Kemudian pada gelas beaker yang berisi aquades, kentang tersebut semakin lama agak membesar daripada bentuk awalnya. Kentang yang awalnya dengan panjang 2 cm dan berat 1,2922 gr berubah menjadi 2,2 cm dan berat 1,3755 gr Kentang mengalami yang namanya osmosis. Osmosis memungkinkan difusi molekul air menyeberangi membrane yang permeable terhadap air tetapi tidak permeabel terhadap bahan terlarut yang ada didalam air. Maka dari penjelasan dan pengamatan kami, kami mendapatkan hasil Hipotonik.

Next, observations on the diffusion process. In the diffusion process, we used a sample of nutrisari as a substitute for CuSO4 Crystals and food coloring as a substitute for Eosin Solution. The steps we took were to clean 4 beakers and then fill each beaker with 50 ml of water. After that, we put 1 spoon of nutrisari into 1 beaker and stirred it quickly. We filled the second glass with 1 spoon of nutrisari too, but in this second glass we did it without stirring. In the third glass, we put 10 drops of food coloring using a dropper by stirring quickly. In the fourth glass, we put 10 drops of food coloring using a dropper without stirring. Then we also did not forget to calculate the time needed for the two solutions to mix with water. Based on the results of observations on the diffusion process with the experiment of Nutrisari samples as a substitute for CuSO4 Crystals and food coloring as a substitute for Eosin Solution. The time difference was obtained in the stirred and unstirred samples. In the beaker glass containing the nutrisari, the stirred nutrisari material only needed 5 seconds to dissolve. While the unstirred nutrisari material needed 55 minutes to dissolve. The same thing happened to the food coloring sample, the stirred food coloring took 2 seconds to completely dissolve, while the unstirred one took 32 minutes to completely dissolve. This happens because of the movement of molecules or solutes from high concentrations to low concentrations. The difference in concentration in two solutions is also known as a concentration gradient. Even though there is no difference in concentration, the movement of molecules can still occur to achieve equilibrium. 

     According to Camphell (2010), diffusion and osmosis are included in passive transport. Where when a substance crosses a biological membrane without expending energy. In other words, diffusion and osmosis occur spontaneously. Passive transport is defined as the movement of substances across the cell membrane without expending energy. This transport goes down the concentration gradient. Passive transport can occur due to differences in concentration from outside and inside the cell so that molecules move through the plasma membrane or cell membrane.

Documentation

Solanum tuberosum Harvesting Process

Potato weighing process

The process of taking NaCl solution

The process of soaking potatoes in NaCl and Aquades solution

Potato length measurement process

 

 

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