Letter to a Biology Student

          Hi, my name is Elizabeth Kardach. I was 15 years old when I started this biology course. I went to Redwood Middle School previously. The subjects I was most interested in at the beginning of the year were my elective creative writing and English. My interests outside of school include piano, violin, drawing, painting, running, and video games. On the first day in this class, I expected a lot of hard work.
          I quickly picked up that Mr Orre's expectations for us were a lot higher than that of other teachers. The first things we were required to do when we walked into class were to take out our notebooks and planners, write down the homework, and start the Do-Now. Nothing more, nothing less. A typical class day involves reviewing the vodcast from last night with the vodcast recappers for a few minutes, and then with the entire class. Then the rest of the class is usually a lab, a blog post, or work time. The homework is daily and consists of a vodcast and CFU. The homework usually takes about 15-20 minutes, depends on how long the vodcast is. We don't get quizzes, but the tests are always very fair and if you study well, you'll do well. The notebook is the most crucial material to this class because we use them every single day. We write everything in our notebooks, and before every test we do a notebook check where we check our table of contents and vodcasts and get points if we have everything in order. The blog is also a very crucial part of class, because we make blog posts usually after every unit or lab. My favorite blog post is my first post on my 20-Time project because of the pictures I included on it. (http://lizziebio.blogspot.com/2017/02/catch-it-before-its-too-late-alzheimers.html). I felt I changed over the course of the year because of some of the presentations we got to do I feel a lot more confident in my public speaking.
          Some of Mr Orre's pet peeves are talking when he's talking, not paying attention, not cleaning up properly, not participating in mindfulness, not participating, not doing the CFU's, interrupting other students when they're talking, not doing the Do-Now, not having homework, not having your notebook ready, not doing the relate and review, etc. Getting a good grade on assignments usually relies on the amount of effort and sincerity you put in. Homework is incredibly important in receiving a good grade. If you don't do very well on tests, the homework can still help you pass. Getting good grades on tests simply requires a lot of studying and reviewing. Three mistakes I made this year was missing some second semester deadlines, since he doesn't accept late work second semester, not studying hard enough for some tests, and missing some unit reflection blog posts. I learned that all of these mistakes can really affect my grade so I took great caution after making them.
          Overall, I really enjoyed this class along with Mr Orre's teaching style. I liked it because it was fun and very informative and Mr Orre was a really nice and good teacher to have this year. I'm taking Chemistry next year because I want access to anatomy in my senior year.

      Signed
        -Elizabeth Kardach

Final 20-Time Post

         My final product for 20-time turned out the way I'd wanted it to, and I was satisfied with it. I created a powerpoint summing up Alzheimer's and what prevents it or causes it, and then I listed symptoms of Alzheimer's disease and symptoms of regular aging and compare/contrasted them. All in a single powerpoint. You can view it here: https://docs.google.com/presentation/d/17JjTVLahi1eA_7uQBRrQOUUcryRKux_lHGlLHv1kPT4/pub?start=false&loop=false&delayms=3000

          I researched a lot on this project and worked really hard on learning the differences between these two common ailments, but this project also took me a while to get started on. So overall, I think I'd give myself an A-. My very first blog post was my favorite, you can view it here http://lizziebio.blogspot.com/2017/02/catch-it-before-its-too-late-alzheimers.html

20 Time Reflection

          I chose to study Alzheimer's disease for my 20-Time project because I have a long line of family members who have had the disease, and I realized I never really fully understood it. My goal was to learn the difference between Alzheimer's and dementia or normal aging. My initial plan to achieve my goal was to just research subtle signs of Alzheimer's and normal aging and be able to recognize the differences clearly. It went pretty well I'd say because now I know how to slow the process of Alzheimer's or even prevent it as well as how it differs from normal aging. If I had the chance to do this project again, I'd probably create a fundraiser for the Alzheimer's association to raise more awareness. I've decided to share the prevention techniques I've learned with my heavily Alzheimer's prone family in an attempt to assist them if they are diagnosed in the future.

Pig Dissection

Pig Dissection

         At the beginning of the pig dissection, we were handed our freshly bathed pig and started out by doing what any normal group of teenage girls would do minutes before cutting into a squishy fetal pig; gave it a name. Jemima. Although Jemima was a dude, we thought the name was fitting, and thus, Jemima's reign began. We started by tying down his arms and legs underneath the dissection mat before we made cuts all the way around the belly button and down his sides near the rib cage. By then we were able to identify the liver, small intestine, large intestine, urinary tract/reproductive system, and diaphragm. We cut all the way up to the neck and found the esophagus, trachea, and the voice box. Over all, the pig dissection was really fun and educating. My group and I had a lot of fun filming our videos, you can watch them here. 

https://www.youtube.com/watch?v=aW1REKnDW6E

https://www.youtube.com/watch?v=8lWrsM2a2Ls

Geographic Timeline Relfection

Geographic Timeline Reflection

    

    One of three major events that happened during Earth's history was the formation of Earth, when it was a planet entirely made of lava and constantly bombarded with comets and meteorites. Another major event that occurred was when the super-continent called Pangea formed, along with reptiles and other types of animals. A third major event was when a massive asteroid hit the Yucatan peninsula, and most dinosaurs went extinct, which is why they aren't around today.

    Earth's history dates back for forever, and we are only an incredibly tiny smudge compared to the rest of the periods. I was surprised by this because obviously it feels like we've been around forever but we really haven't.

    The impact we've had on Earth in such a short time is pretty frightening, considering that we have been able to damage and manipulate it in this time period. It really makes me wonder about what the future has in store for humans.

Prevention: Alzheimer's Blog Post #3

Alzheimer's: Prevention

         I've learned so much more since my last blog post about Alzheimer's disease and more importantly, how to prevent it. I will definitely include the six pillars of Alzheimer's prevention in my final project. One thing I've learned about myself throughout this project is that I actually work very well under stress or pressure or confusion. Or all of the above. Whenever I found myself in a pit during this project, I would stop and think about my next move before acting on it. I feel like that's helped me through my research a lot. I've only encountered a few setbacks revolving around confusion or what to do next for my project. I was able to get over them by taking breaks and stopping to think about my progress.
        The next step in my process is to begin my final product. I'm going to try and piece my entire differences list together within the next few weeks. The great thing about choosing Alzheimer's disease as my topic for my 20-time project is that now I know the differences between the actual disease and normal aging, I can tell whether or not I will have it once I'm older. Alzheimer's is genetic in my family, so it's something we need to be really aware of. I can apply the prevention techniques I've learned to my routine to help slow down the process if I ever find myself diagnosed.

            

Unit 8 Reflection

Unit 8 Reflection

          In this unit, we learned about artificial selection, natural selection, evolution, speciation, and the geographic timeline. We were taught the difference between artificial selection and natural selection, which to me, sounded as if it'd be nearly nonexistent, but as it turned out they were nearly two completely different types of selection. 

Artificial selection involves breeders picking out which animals to breed for which desired traits.

Natural selection occurs when a species is unable to adapt with the phenotypes it was born with, and thus, dies off.

        http://www.csus.edu/indiv/l/loom/wk%2015/dogs.jpg

  

        

http://evolution.berkeley.edu/evolibrary/images/interviews/naturalselection1.gif

                 We also learned what speciation was. Notice how I said we learned "what" it was and not "about" it. That's because I had absolutely no idea this term even existed before this unit. Apparently, speciation is the rise of two or more species from one existing species. I thought this was simply called evolution but apparently it's more specific than just that. Evolution is just the change in allele frequency over time.

          The geographic timeline is still pretty confusing to me, but I'm sure it won't be once we finish our group project of creating an actual timeline on it. 

   I think it'd be interesting to learn more about the dinosaur's downgraded evolution. I want to know how a giant velociraptor could eventually transform into a chicken after a couple billion years.

         As for the assertiveness, I'm still working on it. I'm not very good at being assertive because I often confuse assertiveness with aggression, and I obviously don't want to be aggressive. One thing I did was when the woman making my sandwich at Subway asked if I wanted my sandwich toasted or not I actually said no this time instead of just awkwardly agreeing to it. Baby steps.

Hunger Games Lab

Hunger Games Lab

1) In this lab, all of us were divided into 3 different variations of the same species. There were Stumpys, Knucklers, and Pinchers. It simulated natural selection.

2) The Pinchers were the best for capturing food since they were able to grab the food more efficiently using their pinkies and their thumbs.

3) The population did evolve because the allele frequency for each allele changed gradually over the course of the experiment. The allele frequency for both alleles began at .50 and the "A" allele ended with 0.35 and the "a" allele ended with 0.65. Therefore, the population did evolve.

4) One random event that occurred was where the food was placed and who was closer to it. Whoever ended up being closer had a greater advantage to surviving. A nonrandom event involves the type of phenotype the person was assigned.

5) If the food were larger, it would be a lot harder for the Pinchers and the Knucklers to pick it up, but would be easier for the Stumpys. If the food were smaller, it'd be easier for Pinchers and Knucklers but harder for Stumpys. Ways this could happen in nature is if a predator can't hunt prey that's bigger than itself. 

6) The results would have been different if there was not incomplete dominance because everyone would be either a Stumpy or a Pincher.

7) The relationship between natural selection and evolution is that natural selection causes evolution, since only those with weaker traits are unable to survive and reproduce, those that do survive reproduce and the future generations look only like those that had survived originally.

8) Strategies that people adopted in order to increase their likelihood of survival and reproduction usually involved cheating or stealing or being more aggressive. This would have affected the allele frequency in the population that those who took part in these strategies would have more offspring of their species. This occurs in nature when animals attack each other or rob others for food or survival.

9) In evolution, the phenotype is what evolves, not necessarily the being. Natural selection acts on mainly phenotypes, since these are what affect an organisms ability to adapt in their environment.

10) Are there some species that have underdog traits and still managed to survive and reproduce, even though they were expected to die off?

Unit 7 Relfection

Unit 7 Reflection

          In this unit, we learned all about ecology, including interdependence, homeostasis, cause & effect, and others. I felt more invested in this unit than others because I think it's interesting to learn about what affects our ecosystems and what we can do to help improve the conditions, and also very rarely felt confused or discouraged about learning more about ecology and the environment. 

          The first thing we learned about was, obviously, ecology. We were taught that ecology is the study of interactions between organisms in their environment. This means it's the study of predators, prey, and how other organisms that live together in an ecosystem work together. I learned that a niche includes all of the factors that a species needs to survive, stay healthy, and reproduce and that a habitat includes all aspects of the area in which an organism lives. I didn't think that there was much of a difference before. 

          Interdependence is when all living things are dependent on each other, and abiotic factors, for survival. I thought this was interesting because I didn't think that some living things were so crucially dependent on another to live. Homeostasis, or equilibrium, is when environments are healthiest when they are in balance. Just like the human body, environments are at their healthiest when there is nothing disrupting the natural flow of life. Cause and effect reminds me of karma because if something is thrown out of balance in an ecosystem, it will most likely have a lot of trouble recovering. 

          I feel like I learned a lot more about ecology and environments during the conservation project. It gave me a wider understanding of the true impact that humans have on many different environments across the globe. This project made me more sensitive towards issues like deforestation. 

          

Catch it Before it's Too Late: Alzheimer's Blog Post #1

Alzheimer's: Catch it Before it's Too Late

          I'm doing my 20-time project on Alzheimer's disease. 20-time is a structured, methodical in-class project where students can choose a topic they're genuinely interested about and do a project on it. When starting out with my project, I asked myself the question, "What if there were a way to tell the difference between Alzheimer's disease and natural aging to catch it early on and maybe even stall the progression of the disease?" This is why I chose to commit to Alzheimer's disease as my 20-time project. I believe that people are only hurting themselves when they choose to ignore signs of Alzheimer's early on. By doing this, they won't get a chance to try and fight the disease while they can. There is no cure for Alzheimer's, but there are treatments that can significantly help those diagnosed. 

          I want to be able to create a document of some sort where people can see the difference between what is normal in aging and what is not, and add ideas for natural treatment for the ailment. I will measure my progress and achievements through these blog posts. My plan moving forward is to research even more in depth of the underlying symptoms of AD, hopefully find symptoms that are easily overlooked.

Picture used:
http://brainmaxima.com/go/img/Alzheimers%20Disease.png

Candy Electrophoresis Lab

Candy Electrophoresis Lab

          In this lab, we extracted the artificial food dye from various candies. After extracting the dye, we used gel electrophoresis to separate them by size. When we analyzed the results of our gel, all of our experimental samples were where they were supposed to be, and everything ran smoothly. Some of our dyes spilled a little outside of the designated vats, but other than that, they were fine. 

          Out of the four dyes pictured in the manual, citrus red 2 would be the one to migrate similarly to the dyes we examined in this lab, since it was stated that smaller molecules would be able to move faster through the gel pores than larger molecules.

          Since popular dog food manufacturers appear to put more red dye in the food than any other color, it can only mean that they do that to appeal more to the dog, since animals can perceive red clearer than any other color in the spectrum. This is why it would be common to put artificial food dye in dog food.

          The two factors that control the distance the colored dye solutions migrate are negatively charged molecules and positively charged molecules. The negatively charged molecules move toward the positive electrode and positively charged molecules move toward the negative electrode. Any molecules with no charge will not leave the well.

          The component of the electrophoresis system that causes the molecules to be separated by size are the electrical currents and charges inside the molecules. 

          DNA molecules with molecular weights of 600, 1000, 2000, and 5000 daltons would separate with the least amount of daltons to stretch faster, but not as far as the others. 

New Years Goals

New Years Goals

          A biology goal I have for this semester is to really make sure I understand the vodcasts. I noticed last semester that while I would watch and complete the vodcasts and CFUs, I wouldn't fully grasp the concept or purpose of it. This year, I am going to make sure that after every vodcast I am going to reread and look in my biology textbook if there is something there that I feel I don't understand. Completing every CFU directly after completing the assigned vodcast will also help me achieve this goal, as well as getting really involved with the in-class DO NOW's and looking over them later.

          My second goal for this year is to put my own well being before anything else. I believe that my mental state can affect my work, and I want to make sure that my work is never affected negatively by this. I can achieve this by finishing homework early so I can take the rest of the day off to relax. I will be able to reach this goal because I will be motivated by the fact that once I finish my homework, I won't have anything left to stress over for the rest of the day. This goal isn't just about affecting my work, either. I believe it's important for people my age to take care of themselves in general, since so many seem to just toss that thought aside. I won't allow myself to be one of those people. 

Unit 5 Reflection

Unit 5 Reflection

          In this unit, we learned about the different types and factors of mutations. Since mutations are something that really fascinate and intrigue me, I was able to keep up with this unit very well. The themes and essential understandings were mainly about the causes and effects of mutations and why the appropriate characteristics develop only in the appropriate organs at the appropriate time. Some of the causes of mutations can be by environmental factors such as UV rays from the sun, and most mutations either have a very small effect or no noticeable effect at all. Because of gene regulation, we have a control and or balance of characteristics where we need them. Understanding mutations and their effects were a part of my strengths during this unit and trying to understand gene regulation and the lac operon were my weaknesses. 

          I grew as a student during this unit by learning how not all mutations are deadly and cause diseases, but also understanding that most of the time that is the case. I also found it very interesting that gene regulation is the reason why we don't have four ears or six eyes. Overall, this unit, to me, was incredibly fascinating. Mutations are something I find grasping. 

Protein Synthesis Lab

Protein Synthesis Lab

           1.  There are 8 required steps when making a protein. During transcription, the first step occurs when a section of DNA, known as a gene, is copied by an enzyme. The copy that is produced is called messenger RNA or mRNA for short. RNA is different from DNA because uracil replaces thymine, and RNA is single stranded. The mRNA then leaves the nucleus and travels to the cytoplasm. The next step begins translation, where the mRNA bonds with a ribosome, which will make a protein. The ribosome reads the first three bases called a codon, and determines which amino acid corresponds with that sequence. Each amino acid that is added is determined by the codon read by the ribosome. Amino acids are bonded together, and when the mRNA is done being translated the amino acid chain folds up to become a protein. 

         

          2.  Throughout the several different types of mutations I tested, I concluded that deletion had the greatest effect on proteins and substitution had the least effect on proteins. No, it doesn't matter where the mutation occurs, since the amount of effect will still remain the same. The only way this would be different if the T was near the end is that it would change an amino acid.

"Types of Mutations." Types of Mutations. N.p., n.d. Web. 13 Dec. 2016.

          3.  I chose deletion because it has the greatest effect on proteins. This mutation had a greater effect because it deleted a letter in the sequence without replacing it with anything, therefore completely altering the amino acids in the sequence. It doesn't matter where the mutation occurs, since it will effect the protein greatly without needing a specific location. 

          4.  An example of a mutation that could affect your life is sickle cell anemia. Sickle cell anemia causes red blood cells to become deformed and form a sickle shape, which then clogs blood vessels, can slow or block blood flow throughout your body.

DNA Extraction Lab

DNA Extraction Lab

          In this lab, we asked the question, "Can DNA be extracted from cheek cells, and if so, at what point do you predict you will be able to see the DNA?" To answer this, I said yes, DNA can be extracted from cheek cells because our skin cells have our DNA in them. We found that we would be able to see the DNA after adding the detergent, salt, and pineapple juice to the gatorade mixture and after carefully placing alcohol on top of it. The DNA fell out of the solution as the alcohol was added because the alcohol is nonpolar and the DNA is polar. My hypothesis was "If DNA is in our skin cells, then we will be able to separate DNA from our cheek cells." 

        One of the errors we encountered in this lab was an issue with the lids falling inside of the test tube, rather than closing the test tube. Because of this, we weren't able to effectively shake the mixture we had created with the gatorade, salt, detergent, and pineapple juice. One recommendation I have for anyone conducting this experiment is to be sure to use a cap that fits the right test tube, otherwise, the experiment will most likely turn out wrong for that person. 

       The DNA extraction protocol involved three steps: homogenization, lysis, and precipitation. We used the gatorade to homogenize the cell tissue in our cheeks. We then added soap to lyse the cell membranes and to emulsify the lipids and proteins of the cell. This disrupts the polar interactions that hold the cell membrane together. We then added pineapple juice as a catabolic protease to further break down any proteins called histones that the DNA molecule wraps itself around. 95% isopropanol alcohol was then layered on top of the mixture. Since the alcohol is nonpolar and the DNA is polar, the DNA falls out of the solution as a precipitate right at the interface of the two solutions. The DNA can then be pulled up from the alcohol layer and then collected with a transfer pipette. This lab was important in understanding biological concepts by demonstrating what it means to homogenize a mixture, and what lysis and precipitation mean. 

        

       

Infographic

Egg Diffusion Lab

Egg Diffusion Lab

            The mass and circumference of the egg when the salt concentration increased got a lot smaller, with an average percentage change in mass of -46.0925% and an average percentage change in circumference of -22.11%. A hypertonic solution caused the change because there was more solvent in the egg that left to dilute the corn syrup, causing the shrinkage. The solute moves from areas of high concentration to low until they reach equilibrium.

        A cell's internal environment changes as it's external environment changes by using diffusion to adapt to different external environments in order to survive. When the egg was placed in vinegar, it got bigger because since vinegar is part water, it was able to diffuse the water into it to adapt to the new conditions of the vinegar. When placed in water, the egg returned to it's normal size because of an isotonic reaction with the water inside the egg and the water outside the egg. When the egg was placed in sugar, it shrunk because of the solute leaving the egg.

       This lab demonstrates hypotonic, hypertonic, and isotonic reactions within a cell. Since we are learning about diffusion and these reactions in class, this lab was important for our proper understanding of the subject.

        Fresh vegetables are sprinkled with water at markets so they can stay in a diffused state and remain healthy and fresh. Salting the vegetables would dehydrate them because of a hypertonic solution that would cause the water to diffuse and be replaced with salt water, causing the vegetables to dehydrate and shrivel.

       Based on this experiment, I would want to know why snails bubble when they get into contact with salt. I'd want to find a snail-friendly way of testing this though, of course. I think it happens because of a hypertonic reaction with the moisture on the snail's skin conflicting with the salt. 

Egg Cell Macromolecules Lab

                                                              Egg Macromolecules Lab

            In this lab we asked the question, "Can macromolecules be identified in an egg cell?" We found that proteins, monosaccharides, polysaccharides, and lipids were all found in the egg whites, while the other parts of the egg only had a few. Our hypothesis for the egg white was that if the cell walls include monosacchardies and polysaccharides, then these will also be found when testing the egg whites. There were about 5 of each macromolecule in the egg whites, and the colors observed were purple (monosaccharides), yellow-orange (polysaccharides), purple (proteins), and white-orange (lipids). Our hypothesis for the egg yolk was that if the egg yolk is a giant cell, then all of these macromolecules will be found in it. Every macromolecule was found in the egg yolk except for lipids. The quantitative and qualitative amount of macromolecules found were dark purple, 8 (monosaccharides), golden, 7 (polysaccharides), brown/purple, 8 (proteins). Our hypothesis for the egg membrane was that if the cell membrane is made up of lipids and proteins, then when testing the egg membrane, lipids and proteins will be found. Proteins and lipids were present in the egg membrane, with qualitative and quantitative observations of purple, 3 (proteins), pink/red, 2 (lipids). This data supports our claims that

         Our data contradicts the expected results because while we expected every macromolecule to be present in the egg yolk, it was missing one of them. There weren't any lipids present at all in the egg yolk and because of this, our hypothesis of "If the egg yolk is a giant cell, then all of these macromolecules will be found in it," was false. One error we came across is that for the polysaccharides test, the person testing accidentally put too much iodine in the egg white. Although we only had one error, another possible one could've been cross-contamination of the chemicals. Due to these errors, in future experiments, I would recommend carefully watching how much you put in each test tube and cleaning each dropper everytime you use it.

         This lab could have been improved by maybe keeping better track of our observations and communicating with each other more for more accurate results. This lab was important in understanding biological concepts because the egg is a very good representation of a cell, since it literally is just one giant cell. By interacting with an actual cell, we were able to grasp a better understanding. 

Unit 2 Reflection

       This unit was about the nature of matter, compounds, molecules, bonds, acids, bases, and pH. In response to the essential unit question, I believe that increasing molecular complexity serves as the building blocks for life by learning from the ground-up, starting with atoms, the basic unit of matter, and working your way up to compounds and molecules or the types of bonds. By learning these things in order, it gives us a better understanding of what we're really learning by starting small, instead of diving in head first.
        About the nature of matter, I learned that atoms are the basic unit of matter and make up everything we see and feel in this entire world, including all of us. Atoms are made up of three particles; protons, neutrons, and electrons. Protons have a positive charge and have the same mass as neutrons, neutrons have no charge/neutral charge, and electrons are negatively charged, and are 1/1840 size of a proton while always in constant motion. The nucleus is in the center of an atom, made up of protons and neutrons. I had no trouble remembering the charges of each of the particles, though I occasionally have trouble remembering what the nucleus is and what it's purpose is. Atoms are also the basic unit of elements, which are pure substances that are listed on the Periodic Table with their atomic number. The atomic number of an element never changes.
     I also learned that compounds and molecules are formed by two or more elements and have formulas, which are abbreviations of the number and types of atoms in a molecule (Ex: H20 = 2 hydrogens + 1 oxygen). I have trouble memorizing the different types of bonds, so I realize I have to work on that. Chemical bonds are the energy stored between atoms. There are three types of bonds; Ionic bonds, Covalent bonds, and Hydrogen bonds. Ionic bonds form when an atom gains or loses an electron, covalent bonds are electrons shared between atoms and could have double or triple bonds, and while hydrogen bonds are not as strong as covalent or ionic bonds, they are able to hold molecules together due to slight attraction of positive to negative charged regions. I had a lot of difficulty memorizing the types of bonds and their purposes, so I'm going to keep working on that.
      We learned why water is wet by first going over the properties of water. One of it's properties, polar is the unequal distribution of charge between H and O. It has the ability to form multiple H-bonds, is the most abundant molecule in most living organisms, is less dense when frozen, and has high specific heat - absorbs a great deal of energy.
     I learned that pH is the measurement of hydrogen ions in solutions. I was also taught about the pH scale, 7=neutral, anything larger than 7 is acidic, and anything less than 7 is basic. I might have trouble remembering the scale, so I'm going to study that some more.

Sweetness Lab

                                                                         Sweetness Lab

     1. I believe that monosaccharides are sweeter than the other forms of carbohydrates, since fructose and glucose are really sweet and are monosaccharides. Disaccharides are neutral, since while sucrose is really sweet, lactose and maltose really aren't. And finally, polysaccharides are the least sweet, since both starch and cellulose are really bland.

2. In crystalline form, most monosaccharides are present in a "long chain" structure. Some monosaccharides are modified by cellular enzymes to enhance or change their cellular function. The number and type of monosaccharides used, as well as the position of bond between them, determines the 3D structure of each carbohydrate.

3. All testers gave each sample the same or near the same rating. One reason why it could taste different for one person is if they have different tastebuds, accidentally mix sugars, or dont drink water between tasting.

4. Our tongues detect the majority of the tastes using protein receptors on the surface of the taste cells. The receptors snap together in specific ways, and when they do, the cells send signals to the brain reporting the molecules' presence. Therefore, the testers could rank sweetness differently because although our brains can recognize the same five tastes-bitter, sweet, salty, sour and savory-the suite of chemicals can trigger those signals vary from one person to the next.