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.

Characteristics of Life

Jean Lab

In this lab, we asked the question "How would it affect the jean fabric squares if we put different amounts of bleach in each of the petri dishes they were in?" We found that 100% bleach affected the jeans the most, and, in order, 50%, 25%, 12.5%, and 0% were not quite as effective as 100% bleach, but still did a lot of damage. 100% bleach drained nearly all of the color in the jeans, their once dark blue navy color now a blue white. 50% bleach took away most of the color but still left it blue. 25% bleach affects the texture of the jeans, but not so much the color. And finally, 12.5% and 0% did little to no damage to the jeans. This lab was important for our learning because it taught us more about the scientific method and gave us a better understanding of it.