Peace, mercy, and blessings of God be upon you. Welcome to the final lecture of the Botany Laboratory course. Today, God willing, we will discuss a very important topic: how to perform some chemical tests on plants to identify them. The lecture was originally intended to be live, but due to the weather and the approaching exams, I had to record it. The recording is on my mobile phone, so that at least half the knowledge is available, or even the whole thing. It's the least I can do to have a recording of this lecture so we can understand it. The lecture is divided into two parts. The first part will discuss natural chemicals. Let's start with the files first. Let's talk about it briefly. The attached videos are sufficient. In this lecture, we will discuss secondary metabolites found in plants. After finishing the plant lab and learning about morphology, flower shapes, and how to identify plant families and plant classification, it's now our turn to talk about how to identify or perform these methods. The discovery of active ingredients in some plants is a new approach in botany, but we're doing it manually, meaning you can use or do these things at home. However, we aspire, God willing, to conduct this in laboratories in the coming years, if possible, and if not, to make it part of the secondary metabolites. First, as we mentioned, are phenolics, the largest group of secondary metabolites. As you can see, they include the others: flavonoids and quinones. Their primary function is as antioxidants, and perhaps the most important one is anthocyanins, which are dark purple and found mainly in red caps. We'll see now how their color changes with the pH; it's like a pH sensor. Then we come to terpenes, which are the basic building blocks of essentials, steroids, and carotenoids, which are mainly composed of isoprene limiters. Unit C5's primary source is citrus fruits and mangoes. It may contain carbohydrates, aromas, and alkaloids, which are nitrogen compounds. These primarily function as defense and toxic agents, and their source is many medicinal plants. Now let's talk about the role of secondary metabolites. Unlike primary metabolites such as carbohydrates and proteins, secondary metabolites primarily function as defense agents, specifically by attracting polyoxygenates. Now let's discuss the K2K principle of extraction. For extraction, we must be aware that compounds can be hydrophilic (polar compounds) or water-soluble (water-soluble). These are very important because they dissolve primarily in polar compounds, such as phenolics, saponins, and glycosides. These require sulfates like water and ethanol. Polar compounds require polar modifiers, unlike lipophilic compounds. Nonpolar compounds, which require nonpolar substances like oils, steroids, and terpenoids, need a sulfonate like chloroform or ether for extraction. You can do a simple home experiment to purify polar and nonpolar compounds. If you take an anthocyanin solution and heat it in water, you'll notice that the hyperpolar compounds, like anthocyanins (which are primarily phenols), will float to the top, while the semipolar compounds, which contain impurities, will sink. This requires a home experiment. If you make an ice bath (like this one), you'll see that the hyperpolar components, such as anthocyanins (which are primarily phenols), will float to the top, while the semipolar components, and any nanopolar components, will sink to the bottom. We've already covered extraction methods and will discuss them in the lab. God willing, in the first step of the process, there's mesaturation. Mesaturation is when you perform sokinization on any plant material. During sokinization, you add a sulfonate. The sulfonate can be ethanol or water. Over time, the sulfonate will break down the cell wall. When the cell wall breaks, the active ingredients begin to appear, and the color of the water or ethanol changes depending on the active ingredient present. Its time is spore. Sokinization, on the other hand, is continuous, continuous, and relaxed. It's very important for nonpolar materials, which require more heat and more cycles. It needs a sulfonate like fluoroform and auxin. In this case, extraction is rapid. Stellation, which is specific to essential oils, requires water leaching, especially for oils. Now, let's do a simple case study and look at the Brassicaceae plant. It belongs to the Brassicaceae family and is therefore rich in active ingredients like mustard oil. Glycosites, in addition, are rich in anthianin, which gives them their red color. Let's look at a simple experiment. It consists of several steps. The first step is to boil the red capping leaves with water. The boiling will break down the cell wall, and consequently, the water will turn red. This is a type of sokin, or rather, sokin with... not sokin. This sokin isn't a miscination; it's closer to decoction. Because when I boil the red capping, the cell wall breaks down, and the color becomes almost pink. So, I perform an aspiration or filtration process. The filtration will bring the plant material to the top, and the dye, which is the liquid or colored water, will sink. Here, the anthianin pigments are... well, here. The third step is to purify it again to remove any nonpolar materials. So, how does this work? I put it in water, as I mentioned. Polar materials, such as anthocyanin, rise to the top, while nonpolar materials or nonpolar impurities sink to the bottom, as we discussed in the previous step. The result is pure anthocyanin solution with its usual pink color, but this color varies depending on the pH. So, what's the physical explanation for the color? The physical explanation is that the color changes according to the absorption of light. If light absorbs pink light, the solution becomes pink; if it absorbs red light, the solution becomes red. This process occurs because there is energy involved. We have the UMO (loose n occopide molecular orbital), which contains electrons, and the lower UMO (heist or ocopide molecular orbital), which contains electrons. When an electron moves from the occupied orbital to the unoccupied orbital, it exchanges energy. This energy is the absorption of light, resulting in the transfer of an electron from the occopide to the UMO. The change in color is caused by a change in pH, specifically the photons or photons that undergo absorption when they travel through this pathway. There's a delta signal, which carries energy, and this energy is absorbed, causing the color change. In other words, if you add a base to the base, there's more bonding, more conjugation, more lower energy capacitance, and the color changes more. For example, if I take the solution I prepared earlier, which is the anthianin solution, and use it as a pH indicator, and then add vinegar, what will happen is protonation. The transfer of photons or protons shortens the conjugate system, and consequently, the color will change to red. However, if the pH is 7 and I add only water, without acid or vinegar, the solution will be neutral. If I add baking soda, bicarbonate of soda, or sodium chloride, the solution will be neutral. Bicarbonate, which is what will become the color of basics if you add a stronger acid, meaning any stronger base, what will it be? The color will be approximately yellow, meaning it will range from red (a weak acid, or acid in general) to neutral (the same as the pink of bread), or let's say a medium base (a weak base), to a strong base (the color will be yellow). This means that the positive charge on the ether, which is on the cation, is what caused the color shift due to light absorption. Therefore, this element, the pH, doesn't change. Anthocyanin is a very important antioxidant, and its change makes it an indicator of pH. Since we're talking about antioxidants, they found that most antioxidants, or flavonoids, are concentrated in plant peels. So, they conducted some experiments on fruits like guava, mango, apple, and orange. This experiment showed that alkaloids— specifically, the alkaloid test called Myers-Ban, test FEC3— Saponins, fruits, and flavonoids, which are a mixture of MG and HSL, were found to contain a high percentage of tannins and a high percentage of flavonoids. What are these two? It is a total phenolic compound in guava. They found that it contains tannins, saponins, and flavonoids. The apples have the fewest colloids and flavonoids. In oranges, they found one saponin and one flavonoid positive. This means that this gave me an indicator that mango is the strongest in terms of antioxidants because it contains a high percentage of what? From total phenolics, and of course, these experiments indicate this, and that total phenolic concentration is what matters. They found that this total concentration is present in mangoes in higher quantities, then oranges, then guavas, then apples. But there is something more important than that called IC50, or IC50. The lower its number, the higher the percentage of antioxidants. They found that mangoes actually contain the lowest percentage of this IC50, and therefore it is a stronger antioxidant. They found that antioxidants are related to total phenolics more than they are related to flavones. Of course, we must understand the diagram well because it is very important for understanding the story of the relationship between antioxidants, which is total phenolics in general, and the plant's ability to resist the cell fusion that occurs through free radicals. They made this correlation. Correlation will be covered in statistics, God willing. The R value means that the closer it is to one, the stronger the relationship. They found that phenolics have a strong relationship to antioxidants, with a ratio close to one. Therefore, the R value is close to one, indicating a strong relationship between phenolics and antioxidants. However, they found that the relationship to flavonoids alone is B. Therefore, the active properties of mango peels depend primarily on total phenols, including tannins, rather than solely on flavonoids. This is a very important point. This led them to use plant peels— apple peels, orange peels, and mango peels— for medicinal purposes. They are used in functional foods and natural preservatives as a substitute for synthetic materials in pharmaceuticals, specifically for cardioprotection and as a potent anticancer agent in cytotoxicity, similar to tannins. They are also used in cosmetics as anti-agents. Formulation is related to limiting the activity of free article conclusions. Plant peels are very important, especially those peels related to red capacitors, lemons, and mangoes. This was the first part of the lecture, which dealt with the use of plants or the use of red capacitor as a pH indicator. The second part of the lecture will discuss the uses of plants, specifically methods for conducting chemical tests or diagnoses of some active ingredients using rudimentary, home-based methods. Other methods require very large equipment. This is very important because, while working in the field, we can identify plant characteristics in various ways. We can distinguish foliated oils, dragons, and colors. For example, before we delve into the details of this lecture, we notice that most plant colors are yellow. Why? Because At the beginning of spring, we notice that yellow hues are dominant. The reason is that yellow requires very little metabolic processes, making it easy for them to appear. As we learned in theory, the presence of yellow necessarily indicates the presence of flavonoids, especially the types known as flavones and flaphenols. Anthocyanins, on the other hand, are usually found in different colors in red berries, blueberries, and strawberries. Their color ranges from blue to red depending on the pH level. In red berries, they are pink; in strawberries, they are almost red; and in blueberries, they are almost blue. Naturally, their color changes, and this color indicates the plant's pH. That's why you might notice that some plants have a more acidic taste, while others have a more alkaline taste. This depends on the presence of anthocyanin pigments. However, not all colors are caused by flavonoids; some colors are caused by carotenoids, for example... The red color of tomatoes, for example, is due to lycopene. The orange color of carrots is due to beta-carotene. The almost golden color of melon is due to xanthine. The orange color of sweet potatoes is also due to beta-carotene. We also have aromatic volutes, which are very easy to distinguish. We also have unpleasant or offensive odors, which are usually due to alkaloids. So let's see what we can find in the plant as a whole. In flowers, we usually notice volutes and aromatic compounds. We can find both in the leaves: astringents ( astringent substances) and alkaloids ( potency and toxins). As for saponins, which we talked about in the theoretical lecture, they are glycosidic compounds with a lipophilic and lipolytic component. The water-soluble part is the sugar, and the fat-soluble part is the glycolytic component, which is the part that dissolves in water and fats. So they have both hydrophilic and hydrophobic components. It is usually found in the stems and seeds, while starch is usually found in rice seeds or in the tubes of potatoes, for example. These experiments we will perform are simple, but the correct or more accurate experiments are those of HPLC, which we call High Performance Liquid Chromatography, and which require laboratory work. Let's look at the protocol for this experiment. We will need a tube containing an oxidation-based reagent (I-B) and a solution of iron. We can obtain this solution by taking a nail or a piece of iron, soaking it in the reagent, and then observing that it rusts and produces a red color, which is iron chloride or iron oxide. We can also use iodine, which is a widely available iodine dye, and hot water. Of course, we can obtain all these things at home. We can obtain acid from vinegar, caustic soda, baking soda, and iron solution (iron solution). As I mentioned, we can immerse any iron in acid or water, but this takes longer. Iodine is widely available in pharmacies; it's the same as polidine. And of course, hot water. Then we'll start talking about experiments. We need to keep in mind that in manual experiments, we shouldn't crush the plant or do any more tests because the plant might contain colloids, which could be somewhat toxic. We're doing qualitative, not quantitative, tests. So, it's all about "yes, it has, no, it has." We'll start with a power test that we can easily do at home: the Volatile Oz test. The method is to take a plant like mint or sage, rub it, and apply a poultice. We can then soak it in hot water after rubbing it. You'll find the steam accompanied by aromatic scents, or even if we rub it in our hands and smell it, we'll often find aromatic scents. This is characteristic of many families, especially the Lamiaceae family and some Apiaceae families, such as, for example, the Apiaceae family, like fennel, and some composite families, such as chamomile or camomile. If the positive results give an impression of the presence of essential oils, it's a simple test we can easily do. The second test is the tannin test. We mentioned in the theoretical lecture that tannin precipitates iron, glucose (polysaccharides), and proteins. Therefore, we need to find a plant that contains tannin. The best thing to do is make a cup of tea and let the tannin steep for a long time. You'll notice its color darkens, which means it contains tannin, like this. Then, add the iron solution we saw that I told you about. This is a simple iron solution, so the tea changes color from brown to deep blue or black. In this case, we confirm the presence of both, and I gave you a simulation of it at the end of the lecture. But remember that there is a second test. So, how will I benefit from this story? Why did the color become deep blue? What did both do? They precipitated the iron, and this is a very important point: preventing iron absorption and precipitating it. This gives us the impression that the theory that we shouldn't drink tea after taking iron or folic acid is true because the iron or tea will actually inhibit iron absorption, and therefore we won't benefit from the iron. The same applies to calcium, polysaccharides, and proteins. So, these two precipitate. Now, let's see what the reaction is. The context tells you that the compound present in the, in the, or in the, which is the we used, which is iron oxide, and we used rusty water, and the mechanism is the reaction of the complex. Complex, and this complex is what gave this color. This is a very important experiment, and you can do it at home easily and simply. As for the second experiment, which is the saponin experiment, what is saponin? It's a glycoside compound made up of hydrophilic and hydrophobic particles. Its function is to cleanse, which is why we said it's related to soap. It's primarily used in fat burning, especially in nutrition and contact natural detergents. It foams, so the best thing to do is to get the plant material you want and put it in a test tube. The easiest way is to use fenugreek or fenugreek seeds because they are rich in saponins. After grinding them into a powder, put it in the test tube or a glass you have at home, add water, and keep shaking it. You'll notice that foam forms. If this foam disappears immediately, it means there are no saponins. If it stays for a long time, it means there are saponins. Of course, fenugreek contains saponins, so this test is very easy to make. If the formation of a stable, persistent, and permanent substance means... The foam that dissolves doesn't go away afterward. As for the alkaloid test, this is a somewhat risky test. For this test, we need to add two substances together: the acid extraction (which is bengar) and, to perform nitrification, we add bicarbonate of soda. We then use the plant or medical substance we want to test, which could be clinical cobalt, a plant substance, or whatever it is that contains alkaloids. Tea is also suitable because it contains caffeine. We add the acid, and then we add sodium bicarbonate. In the end, a precipitate will form. This precipitate indicates the presence of an alkaloid. However, the test is very basic, and the result is very approximate. It requires extreme care to perform it properly. The next test is the starch test, which is very important and very easy. We can use a polidine solution or The iodine available at the pharmacy, and if we take, for example, potassium nitrate strips, it will change color to a dark blue. This is evidence of the presence of starch. Of course, if you do the same with corn, corn powder, or cornstarch, you will notice the same result, indicating the presence of starch. If you do the experiment with rice powder, you will also notice the same color because it contains starch. So, what happens is that it reacts to a black color. The experiments we took to repeat are: one for starch, two for alkaloids, three for saponins, and four for the other two. These are the four important experiments we took, and to summarize them: First, for voltaic oil, we performed a refractory heat test, which gives us an intense aroma, meaning there is voltaic oil. Second, for saponins, we perform an elution test, which gives us stable foam. Third, for alkaloids, we add a ferric bicarbonate, which gives us sediment (a precipitate), and finally, for starch. Iodine gives us deep angiotensin, which is primarily a red color. Of course, experiments are important, but HPLC is the most common. Additionally, some experiments or tests require more precision, not manual testing like this one, or tests that aren't home-based. These are based on scientific experiments. However, at this stage, if you were to complete these four experiments at home, it would be very important. Currently, there's time to complete them, but God willing, if we're still alive and we study this topic, this will be a supporting activity alongside the herbarium. We'll allocate 20 points to the herbarium, maybe 10 to this activity and 20 to the other activity. Now, let's look at some infographics that support the topic, and then we'll show some videos that further support it. Okay, okay, God willing. Let's look at the infographics together. We'll start with the first infographic, which is related to the antioxidant experiment. And of course, the experiment we mentioned, the second metabolites play a key role in... It works as an anti-inflammatory like infosanin and can also act as an anti-drug. The experiment they conducted on antioxidants in fruits found that mango has the highest concentration, followed by orange, and then guava. This is, of course, the result of scientific experiments. They found that mango has the highest total content, and we said that this is important for antioxidant activity, not for flavonoids. Nutrients are very important. Then we talked about the red capacitance experiment. This experiment involves taking red capacitance and adding heat to it in an aqueous solution. In other words, the decoction breaks down the cell wall, and its color turns white. But after that, we filter and purify it to get rid of the polar compound oxidases, which sink to the bottom, while the pure compound remains on top. Then we'll talk about how this is neutral. If we add an acid and a base, the acid will turn red, and the base will turn a pale green or yellow, primarily if the chemical agent is positive visually. As for the other experiments, the color will be as you see, blue after adding frac chloride. This is in the official test, but in the manual test, we add frac oxide. Be aware of this. Regarding the alkaloid, in the official test, we use an agent called Myers Reagent, which is cream preseptate. However, in the manual test, we use a mixture of vinegar and soda bicarbonate. This was the first infographic. The second infographic, the second one, talks about the experiments in general, as if summarizing all the experiments. For example, the first experiment with polyethylene chloride involves mint leaves. When you rub them, you notice that the aroma comes out, mainly saponins. The thing is clear, he's checking the aqueous solution with the plant mixture or with the plant material, and the foam looks like this. The next two tests, as we said, produce a dark blue color, and the third test, which is the starch test, also produces a dark blue color. As for the alkose test, it produces a cream or sedment precipitate. The last graphic is important, of course, because it mainly shows the official tests. Here I'm talking about the official tests. Notice here we're talking about the tests that will be done in the lab, which is detecting alkaloids using the Wingers test. The Wingers test involves using this reagent, Wingers reagent, and an aqueous solution of the plant extract. The color will be reddish- brown precipitate. So, first of all, the Wingers test is different from the Mars test. What does the Mars test give? It gives sedment, while the Wingers test gives a manual cream that also gives precipitate or cream sedment precipitate. Therefore, there's a difference between them. For the tannins, in the official identification test, we use chloride, which gives dark blue, possibly a greenish-black cherry color. However, in the unofficial test, we use ferric oxide, so be careful with that. As for saponins, in all cases, we will use the same test; it will be foam. Therefore, we repeat the reaction or screen result reference, which is the official one. For alkaloids, the reagent is pyrexate, reagent cream, and precipitate. We didn't cover steroids, but it's required that we say it's a slimming whiskey test, which gives red, darker, and lighter colors. For flavonoids, we use lead acetate reagent, which gives yellowish-brown precipitate. As for the red capacitance pH indicator, we used Spectrum and discussed that the higher the acidity in a certain direction, the redder the color. So, pH 1 is the most acidic and reddish, but in this direction, pH 2 is less acidic, and pH 3 is the least acidic, so the acidity decreases. Until it reaches a pH of 7, if this red is lemon juice, of course, the lemon juice will be close to pink in color, but after that it will start in the alkalinity stage, the weak alkalinity pH is 8, then I get soda pH 10, green, but the strong alkalinity pH 14, for example, what color will it be? Yellow, strong base indicators, turn yellow-green. You can try it at home. Soda will give you a green color, and lemon will give you a color similar to mauve. As for the original pink, it's at pH 7. Regarding the videos, I've already sent them to you on WhatsApp, so there's no need to include them in the lecture. However, I strongly recommend that you listen to them. Now, let's do some simulation models that can illustrate some experiments. Let's start with the tannin simulation model. This model is very simple. We have a dropper with iron in the tip and a teacup, which is brown. Now, we'll start. It gives me tannin detection. There's no detection yet because I haven't added anything yet. I added the first drop of purity, and it starts to change. Trace detection and wick positive increase until it reaches storage, and it will change. Why, at the end, does the blue color continue until it reaches the word "tannin detection," which is saturated, and the complex begins to form until it reaches the word "saturated positive"? The color then becomes as you see it, dark blue, and this is evidence of the presence of tannins. The scientific explanation, as written, is that iron tannins form a complex called iron tannin complex, which produces a blue- green or black color. The ink stain is evidence of the presence of the second tannin. Of course, this was done using one of the artificial intelligence tools, which is MiniMax, and the experiment is simple. In some of the other experiments, I also did them using Gemini. It might help to understand some of these experiments. Gemini, God willing, we will find them, for example, the starch and fish net experiment. But it is very possible to do all the experiments in the same way. MiniMax does them offline, but in order for the video to be complete, I prefer that we listen to the videos and then talk about it. So, to conclude the lecture, let's start talking about the two videos. These videos were also created using artificial intelligence through the Notebook program. We'll begin with the first one, the one about mangoes and mango experiments. Many of us see strange things happening in the kitchen, things that seem like magic. But what happens if we take this magic and turn it into real science in a lab? That's exactly what we'll discover today. We'll talk about the hidden power of plant chemical compounds, or what we call phytochemicals. Our story today begins with something that can be found in almost every home: red cabbage water. If anyone has tried it before, they'll understand what I'm talking about. What's the secret that makes its color change in such an amazing way? Imagine taking this cabbage water and adding two drops of vinegar, for example. Suddenly, the color turns a bright red. It's like a magic trick happening right before our eyes. Okay, that's if we add acid. But what if we try adding... When you use something alkaline or a strong base, the color changes completely again. This time it turns yellow, and the whole thing becomes even more mysterious. Of course, she means yellow when the pH is 14, which is a strong base. But if it's a weak base, it won't be yellow. For example, in soda, it will turn a color that's almost green. So the color change also depends on the pH, regardless of whether it's an acid or a base. But even bases have pH levels of 14, 13, and 12. So, depending on the pH, the color and its effects change. But the big surprise comes when we use a weak base like baking soda. Here, the color changes; it turns blue-green. This shows us how sensitive this liquid is to any chemical change, no matter how small. Okay, so we've seen the magic. Now it's time to understand the science behind it. What is the secret identity of the substance that makes all these changes? The hero of our story today is a component called anthocyanin. Anthocyanin is not just a powerful antioxidant compound, but it's also... The molecule responsible for the beautiful red or purple color of cabbage, and at the same time, it's what makes it a natural indicator of acidity, alkalinity, or pH. So, the important question is, how does it change color? The subject might seem like complex chemistry, but it's actually quite simple and interesting. When we add an acid or a base, the chemical structure of the molecule itself changes. This change affects the way the molecule absorbs light. So, when the way light is absorbed changes, the color our eyes see changes with it. It's that simple. Now that we've talked about this amazing molecule, let's delve a little deeper to find out exactly where it comes from and what its chemical family is. We can imagine that plants have, let's say, two chemical toolboxes. The first box contains the basic things for the plant to live, like sugars and fats; these are called primary metabolites. The second box contains specialized tools— things for self-defense, for attracting insects for pollination, or for giving the plant its distinctive color. Our anthocyanin is one of these tools. The second box, phalanphianin, is just a small example, a drop in the ocean of a huge chemical arsenal that plants make to defend themselves and communicate with their environment. All these compounds have a collective name: phytochemicals, or in English, phytoclase. The word phyto actually means plant, and this includes many families such as flavonoids, tannins, and alkaloids. The thing that many of them have in common is that they have very strong antioxidant properties. Okay, great, if these beneficial compounds are present in almost all the plants around us, the question that arises is how do we measure this strength? How do we know which is stronger than which? To answer this question, we will use a very interesting scientific study. This study decided to look for these hidden powers in a place no one would expect: in a part of the fruit that we usually all throw away in the trash—the peel. Look at this table; it shows us something amazing. Each of these fruit peels has a different chemical signature. Exactly. For example, mango peel is full of something called tannins, while apple peel has almost no tannins at all. This shows us that each plant has its own chemical arsenal. Now, before we get into the numbers and results, let's clarify an important point: what exactly is antioxidant activity? Simply put, it's the ability of a compound to fight harmful molecules in our bodies called free radicals. We can think of it like a bodyguard protecting the body's cells from any danger. Okay, back to the study. The graph in front of us shows us the first important result: the total amount of phenolic compounds in each peel. It's simple: the longer the column, the more of these powerful compounds that peel contains. If we look closely at the graph, we'll find that the winner in the quantity race is mango peel, by a significant margin. It contains more than double the amount of phenolic compounds found in apple peel. This is a truly amazing result. But here's an important question: is the quantity... The large quantity doesn't necessarily mean greater strength. That's why scientists don't rely solely on quantity; they use a more precise scale called EC50 to measure true effectiveness and potency. And here's the surprise: this scale, specifically EC50, operates on an inverse system. The lower the number, the greater the antioxidant power. Yes, note that the lower the number, the greater the antioxidant power. A very important point: when we look at the number of mango peel, we find it very low. This confirms that mango peel not only contains a large quantity of these compounds, but also very active and powerful ones. All of this leads us to a very important conclusion: Now, in the second video we can show, which is the last one, the plant investigator, every plant around us is actually a small chemical factory full of compounds and secrets waiting to be discovered. In this explanation, we'll play the part together. Plant Investigator: We'll uncover some of these secrets in very simple ways that any of us can do. Let's begin the investigation. The question that starts the whole story is simple and direct: What's hidden inside a plant leaf? The truth is that every leaf, every stem, every root contains a cocktail of chemical compounds. These are what give it its scent, taste, and the properties that distinguish it from others. These compounds are called active ingredients, and these are exactly the clues our investigator is looking for. They are responsible for almost everything, from the invigorating scent of mint to the lingering taste in our mouths when we drink strong tea. Now, let's open the first file in our investigation: the mystery of scents. This is perhaps the easiest case we can solve because it relies on the sense of smell. But the clue we're looking for here— yes, when I said that when we make tea, and the tea is strong but without sugar, it tastes bitter—this bitterness or tanginess is a result of the large amount of tannins in it. Tea, but if you make weak tea, you'll notice that even without sugar, the bitterness is less because the caffeine will be higher. The volatile oils are the plant's secret weapon. The method here is incredibly simple. First, choose a leaf with a strong scent, like mint or thyme. Second, rub this leaf very well between your fingers. The result is immediate: the strong scent that emerges is the direct, physical evidence of the presence of volatile oils. So, we've found the first fingerprint in our plant crime scene. Okay, let's close this file and move on to the second case. The evidence here is a little different, and we'll talk about something called tannins. These are the substances responsible for the pungent or astringent taste. You know that feeling we get when we drink strong tea without sugar? That's the tannins. The test here requires two simple steps. First, soak a piece of the plant in some hot water, and then add a few drops of iron solution. He suggests a very clever trick: simply soak a rusty nail in a little vinegar and water and use the water. A brilliant idea, right? And here's where the crucial moment comes in. Suddenly, the clear water turns dark blue or blackish-green. This dramatic change in color is what reveals the truth and confirms the presence of tannins. The evidence is caught red-handed! The third case is more complex and involves a move: we'll look for a compound called saponins. From the name, we can guess the evidence we'll find: the foaming phenomenon. The method is very simple. All we need to do is put a piece of the plant in a bottle of water, seal it tightly, and then give it a good shake. The indicator here is clear and straightforward: if a persistent foam appears— meaning the foam stays and doesn't disappear quickly—then this is strong evidence of the presence of saponins. Simply put, these compounds work exactly like natural soap. Great! Now, our detective... He needs to add a few quick tools to his kit to uncover more evidence. These are quick tests for other important compounds. Let's look at them quickly. The first quick test is for starches, and most of us probably remember this experiment from school. The target here is starch, and the method is to add a drop of iodine to a crushed sample of the plant. If the color turns dark blue, then we have found our evidence. The second test is for alkali compounds, or alkylides, but here we must stop and pay very close attention. The source warns and emphasizes that this method is very approximate and not at all accurate. It relies on vinegar and sodium bicarbonate. If a precipitate forms, this could be an indicator, but the result is not at all certain, and we must handle it with extreme caution. After we have gathered all this evidence, it is time to write the final report for the investigator. Okay, so we have basically presented the videos, and now we want to go back one last time to Gemini. So, can we look at the experiments I did or the simulations I did? For example, a simulation for detecting starch. See if it works or not. Try opening it. Hopefully it works because the internet is down. I tried detecting alkaline. No, I don't think so. I did the simulation. A simulation for detecting dragons. A simulation for detecting soap in fenugreek. What's the game? Of course. Anyway, to do something like this, we can do it together because, honestly, the Mini Max is better for it, but I've opened the game. First, you choose the first thing, then you tell it to design a simulation for detecting saponins in fenugreek by soaking fenugreek extract in water and shaking it vigorously until a stable foam appears as evidence of the presence of soap. Of course, there are other sites that are better for these design things. We tell it, okay, it can work, meaning in an offline way like the one I told you about. Of course, it wants to work, and the saponin detection simulation is working. I will design an interactive simulation for this. The chemical experiment will allow you to simulate, of course. Now, let's do it. We'll open it correctly, so we got the experiment as follows: The first step is to start by adding fenugreek seeds. Okay, we tell him to add fenugreek seeds. He adds the fenugreek seeds. Then add the extracted water to the water. After that, shake the tube vigorously. Of course, foam should appear. The foam is a result of the presence of... but of course, the foam isn't clearly visible. But here, it's visible. If it gets bigger, there are bubbles. We can write to him again, showing the foam clearly. For example, let's clarify it by coloring it, for example, with a red color, just so it's visible. See what he tells us. Of course, with this method, which is the Gymnast method, you can simulate all the experiments, which is the starch experiment. We can do the starch experiment for you too. The second experiment we did was the chloride experiment. So, you can do this simulation method. Of course, there are many programs that do these things, such as AI, for example, AI, Google, Google Studio, Mini Max, for example. The example is in Many things do these things. The Manos Manos does them to a great extent, but the Mini Max is the best. Unfortunately, it's not free; it only gives you offline access. Even adding fenugreek seeds—the first step is adding water, the second is shaking the tube, and it produces a red foam, as I mentioned. Just to clarify, we can do any experiment this way. And with that, we've finished the Botany Lab curriculum. I hope you're all successful in this course. We have 10 lectures on the webinar that will be required for the final exam. All the PDF files are available except for the last two, which are too large. I couldn't upload them to the group, but I couldn't upload them to the webinar because they're too big and our internet is a bit slow. However, I'll upload them to the webinar for you. The exam covers the entire curriculum. The final lab exam will include more essay and inferential questions than multiple-choice questions. The exam will be on 5/3/2026, in one session only, from 11 to 12. The exam duration will be 50 minutes. The exam will be a qualitative exam, meaning it will cover everything we have learned: herbarium, how to create a herbarium, plant classification, identifying flowers on leaves, plant families, and today's lectures. Happy New Year, and I hope you all do well. M.