How the Size of Molecules Affects their Movement Through Semi-Permeable Materials

Abstract:

This experiment was conducted in order to find scientific proof of diffusion and osmosis occurring, it also sought to find proof of which molecule was larger; glucose or starch. A total of eight controls were conducted using a variety of laboratory tools. Dialysis tubing was used to determine what molecule was larger and also exhibited signs of diffusion and osmosis.

Introduction:

In many previous classroom lessons, it was taught that starch is larger than glucose because it is made out of many more molecules linked together in a long chain. In this experiment, it was actually the case that we had to find proof that starch was larger than glucose. Not only that, but we also had to be able to measure the affects of diffusion and osmosis. The general hypothesis was that the smaller molecule, glucose, would be able to diffuse through the semipermeable membrane of the dialysis tubing while the larger starch molecule would be to big to pass through the membrane. Dialysis tubing is used by doctors to replicate the function of the kidneys. The tubing only works by diffusion and osmosis, it cannot filter. Benedict's reagent is semiquantitative, this means that although it will show it there is or is not glucose is a solution, it will not tell how much. Glucose reacts with Benedict's because the Glucose contains one -CHO group that reacts with the free Cu++ ions in the Benedict's solution. This ends up changing color because of the reaction. Iodine reagent reacts with starch because part of the starch molecule has spots that the iodine reagent fits into when the starch-iodine complex changes shape after being heated above 35 degrees. Iodine reagent contains the element iodine and ions of the element iodine. Iodine reagent only appears blue when the element iodine is in the presence of the iodide ion.

Materials and Methods:

2 eyedroppers 1 beaker water glucose starch 3 inches of dialysis tubing 1 three beam balance                           ruler                        2 four-inch lengths of string

A 3 inch length of dialysis tubing was cut, and rinsed under water until it became soft. It was then tied closed on one end with string and filled with water and tied closed at the opposite end. This package of water and tubing weighed a total of 7.45 grams before the experiment. A beaker was then filled with 50ml of glucose and 50ml of starch. The combined weight of the starch, glucose and beaker was 201.69 grams.

To test for diffusion and osmosis occurring, the packet of tied-closed water-filled dialysis tubing was placed in the beaker containing the 50% glucose, 50% starch solution. This experiment was set to the side for 45 minutes while the control experiments were tested. The first control was with glucose. Two ml of glucose was put in a test tube in a beaker of boiling water with two drops of Benedict's Reagent for one minute.  The second control was with starch. Two ml of starch was put in a test tube in a beaker of boiling water with two drops of Benedict's Reagent for one minute. The third control was with glucose. Two ml of glucose was put in a test tube in a beaker of boiling water for one minute. After one minute, the test tube was taken out of the boiling water and placed in a test tube holder. Two drops of iodine were then added to the glucose. The fourth control was with starch. Two ml of starch was put in a test tube in a beaker of boiling water for one minute. After one minute, the test tube was taken out of the boiling water and placed in a test tube holder. Two drops of iodine were then added to the glucose. The fifth control was with water. Two ml of water was put in a test tube in a beaker of boiling water with two drops of Benedict's Reagent for one minute. The sixth control was with water. Two ml of water was put in a test tube in a beaker of boiling water for one minute. After one minute, the test tube was taken out of the boiling water and placed in a test tube holder. Two drops of iodine were then added to the glucose. The seventh control was with glucose and starch. One ml of glucose and one ml of starch was put in a test tube in a beaker of boiling water with two drops of Benedict's Reagent for one minute. The eighth control was with glucose and starch. One ml of glucose and one ml of starch was put in a test tube in a beaker of boiling water for one minute. After one minute, the test tube was taken out of the boiling water and placed in a test tube holder. Two drops of iodine were then added to the glucose and starch solution.

Results:

After the beaker of the 50 ml starch and 50 ml glucose solution had been left for 45 minutes, the packet made from dialysis tubing was removed weighed on a three beam balance. The beaker was weighed next. The package of water and dialysis tubing weighed a total of 7.45 grams. The beaker The combined weight of the starch, glucose and beaker was 201.69 grams. Both measurements of weight were exactly the same as when they were first measured. The dialysis tubing was cut open at one end and an eye dropper was used to put 2ml of it's liquid contents into two test tubes. The test tubes were then placed in a beaker of water and were left until the water was boiling. Two drops of  Benedict's was  then added to one beaker and that beaker was left in the boiling water for another minute. The other beaker was removed and placed in a test tube holder. Two drops of iodine were placed in the solution.

Solutions color when properly mixed with reagents in this experiment:

Controls:		Tests:
Mixture:	End Color:	Mixture:	End Color:
Glucose & Benedict's	Brown	Starch + Glucose & Benedict's	Brown
Starch & Benedict's	Transparent blue	Starch + Glucose & Iodine	Dark brown-purple
Glucose & Iodine	Transparent yellow
Starch & Iodine	Dark brown-purple
Water & Benedict's	Transparent blue
Water & Iodine	Transparent yellow
Starch + Glucose & Benedict's	Brown
Starch + Glucose & Iodine	Dark brown-purple

Discussion/Conclusion:

The reason why the weight of the dialysis tubing full of water and the beaker of water weighed exactly the same after the experiment as when it begun, was because as glucose molecules diffused through the semipermeable membrane of the dialysis tubing trying to get to equilibrium, the water in the dialysis tubing moved out of the tubing package by osmosis to get to equilibrium in the container and the dialysis tubing packet. The test tube that had the liquid from the dialysis tubing packet turned brown when tested for glucose with Benedict's but the septate sample from the same place did not change color when tested with iodine. This means that only the glucose molecules were able to diffuse through the membrane. This allows the conclusion to be made that the glucose molecule was able to diffuse into the tubing because the molecule was small enough to fit through the membrane. Water  molecules were inversely able to leave the tubing also because of their size. The starch molecules were to large to be able to get through the tubing without some sort of facilitated diffusion or active transport. Because the tubing in not alive, it is not able to produce ATP to be able to move the larger starch molecule through its membrane and so the starch remained outside the tubing package. This is a perfect reference to why the body must use enzymes such as amylase to break down starch before it can use the molecule, because otherwise, the starch molecule would be to large to be able to diffuse through the cell and the body would do something efficiently rather than waisting time and energy trying to bring the starch molecule inside the cell before it breaks it down. The many controls for this experiment ensure accuracy in the final conclusion by vitrifying that iodine and Benedict's reagent do not react unexpectedly with anything other than what they are suppose to react with.

Resources:

http://uk.answers.yahoo.com/question/index?qid=20071024095219AAn7vOZ

http://answers.yahoo.com/question/index?qid=20080821185510AAj0O4a

http://www.medicinenet.com/dialysis/article.htm

http://wiki.answers.com/Q/What_is_the_reaction_between_glucose_solution_and_Benedict's_solution

http://www.elmhurst.edu/~chm/vchembook/548starchiodine.html

Health Essay

There are many ways that one can benefit from staying physically fit. The first benefit that I would like to address for the purposes of this essay is that physical activity increases the amount of endorphins produced by your body. Endorphins are chemicals that are produced by your pituitary glands. They are neurotransmitters that travel through your bloodstream to your brain. Endorphins contribute to your level of happiness and so people who are physically active are generally happier than people that are not and thus they are less likely to suffer from things like stress and depression. I don’t suffer from either of those but perhaps that can be attributed to my proficient physical exercising! Many times Doctors will even prescribe different exercises to patients who suffer from stress or depression to help them fight the symptoms. The second health benefit is that staying physically fit is good for your heart. My family has a history of heart disease on my mother’s side so I realize how important it is to stay physically fit. The third health benefit that I would like to point out is that exercising helps to stimulate the formation of neuronal connections in the brain and so people who are physically active are actually smarter than if they just did nothing. The way this works is that when you learn things your brain creates neuron connections that help it send signals faster. The more connections of neurons you have in your brain the smarter you are. When you exercise you are basically teaching your brain about different things like coordination and agility. This creates more new connections between neurons and helps your brain to process information quickly. Interestingly the connections that your brain makes for doing things like walking can also carry signals generated by neurons that have nothing to do with walking because each neuron can have thousands of connections. There is currently a lot of research going into finding out why this happens but for now we will all just have to be satisfied knowing that exercise makes us smarter!

After high school I don’t plan on doing any sports or anything but I will probably stay physically active by biking. I bike different places all the time because it is a lot less expensive than taking a car because you don’t have to waste money on gas; especially if you are just going to a friends house. I don’t think that there is anywhere that I go in Hampden that would take me more than ten minutes on a bicycle that and considering that my top speed on a bike averages at 18 miles per hour I feel like I could do pretty well if I ever needed to go that far but like I said hampden is a small town. I also like riding a bike because I like being ‘green’ or environmentally friendly. The earth is my favorite place so I try to do my best not to pollute it.

Besides the economic and environmental advantages of biking, there are also many physical advantages. One major advantage is that this is a great cardiovascular exercise. When you pedal a bike you are using more leg muscles than you would if you were just walking. Using your muscles is good for blood flow as well as getting your heart pumping. All of this contributes to your physical health and it will allow you to live a long life full of vitality.

Bibliography:

http://www.helpguide.org/mental/stress_signs.htm

http://www.webmd.com/depression/default.htm

http://yourlife.usatoday.com/mind-soul/story/2011-10-31/Happy-You-may-live-35-longer-tracking-study-suggests/51016606/1

http://en.wikipedia.org/wiki/Endorphin

Biology Summative Essay

Before taking this course, I understood that I had a fair but vastly brief, understanding of biological concepts. I learned many things during this study of the biological world. For the purposed of this essay I will now address three of which. The first was osmosis, for some reason in all past classes the definition of osmosis that was used was “diffusion except with water”. I had this definition memorized and in every class previous to this one it was only expected that one could define osmosis, not apply it, and so I went since the concept was introduced to me, thinking that osmosis was the process of particles going to equilibrium in water, instead of the water itself moving to find equilibrium as I now know is the true definition.

The second misunderstanding that I would like to point out, or better put, lack-of-understanding, was the processes that occur in the cell cycle. Based on what I had previously been taught, I believed that the cell cycle was much simpler than it really is, I thought that interphase was an actual step in the cycle, but I now understand that it is a part of cellular division as well as the normal functions that the cell must carry out. Third on my list of misunderstandings, my previous belief on the operation of neurons was that they simply fired electrical pulses. This was the greatest misunderstanding and lack of understanding that I have had. I had no idea how complex the workings of neurons were and I wrongly believed that I knew all there is to know about them. Neurons are the most amazing work of nature, their complexity together hardly is as complex as to how they can possibly work together to perform such incredible feats when one examines how a single neuron functions if it were alone. The process of sending signals is a chemical process much more than it is an electrical process. I find it amazing that this fact was never made evident to me prior to this class, or that I never endeavored on my own to understand how my own mind works.

During this course, I learned many remarkable facts and aspects of how the world we live in works. This class was equally about applying knowledge as it was about learning it. As a learner I found that I succeed with learning the information as long as I knew what information I needed. When it comes to applying information, I feel as though my difficulty was taking information that I knew and using it to answer a question that was not simply about reciting the information. This is the first class that I have ever taken where I had to use what I knew in that way. It sounds easy when simply stating it, but in reality, this completely new experience goes against years of what you might be able to call 'mental programming'. Being very use to memorized learning methods where if one simply read the text they could be quizzed on the text, I found it difficult to do otherwise. I found that the best tool for me to help apply my knowledge was to read the text while going over my notes from class, then to draw and label a diagram. My best memory of this and most effective tool was during the section on the digestion. I drew a complete human digestive tract and copied all of my notes onto it and put them in the location that they pertained to. Another activity that I found useful was the dialysis lab. This lab really showed me how diffusion and osmosis can act separately and how they can affect each other. This lab truly enhanced my understanding of how matter tends to seek equilibrium. It also showed how to determine which molecules are too large to diffuse without any energy needed such as when cells use energy for integrin transport proteins to allow large molecules or charged particles (ions) into themselves. The unit that I most enjoyed was macromolecules and the periodic table of elements. Personally I am absolutely fascinated by the mechanics of how atoms bond and why they bond. Electronegativity was a newly introduced concept for me. The periodic table print-out showing the electronegativity of atoms V.S. their size was very helpful because I was able to visualize how the atoms decrease in size as electronegativity increases. Learning about the elements was my favorite activity.

I have acquired many new skills during this time of biological study. Among the most useful of these are being able to convert metric numbers based on decimal places, writing lab reports, being able to interpret bohr models, and being able to predict offspring using punnett squares. Converting metric units is a useful tool that I will be able to use in both scientific and mathematical studies. I will need to write lab reports many times in the future so I am glad that I was able to get practice now so that I will be better off in the future when I have to write them. It is important to be able to use bohr models to represent atoms and atoms that are bonded together, and being able to predict the possible outcome of offspring based on the traits of two parents is helpful for any experiments involving cross breeding plants to produce better varieties. These skills help me to communicate with the scientific world as well as interpret scientific data with much greater accuracy and ease. This will help me with future labs and other various reports.

I am happy to submit this portfolio for grading, but not to represent what I have learned. I feel as though there is so much that is not in it. This portfolio is important for my grades which makes it important to me, but only in that one way. If I were going to put only what I thought was important into it, it would be a collection of diagrams and notes with the exception of four or five printed documents. In the future I think there should be a section of the portfolio titled “Stuff I would keep” This would be a section for copies of documents that the student would keep to teach another student about a topic or subject.

My proudest moment in Honors biology was during the dialysis lab. My lab partner was absent and we had not previously been able to agree on what the best way to conduct the experiment would be. I went along with what I thought was right and what seemed logical to do. During the whole experiment I was unsure how to answer the question of proving if starch or glucose was bigger. When I finished the experiment I figured it out based on the fact that the starch could not diffuse. I felt so relieved because I had no idea prior or during the experiment if I was doing the correct things then it all worked!

If I could view my self from afar and see myself doing what I have done in this class I would probably not intervene except for the few times that I forgot to do an assignment. After reading the initial narrative essay that I wrote at the beginning of the term, the first thing that I noticed was that I have improved with my grammar. Also after reading what I wrote I can elaborate even more and use use things I wrote about like pH in other areas of knowledge that I acquired later on in the semester such as kidneys and electron transport chains.

Morphological and Scale Model of a Centriole

Morphological and Scale Model of a centriole

Centrioles are found mostly in the eukaryotic cells of animals. Plant cells do not contain centrioles. These organelles mostly come into use during cellular mitosis. Although they do have the same structure as cilia and flagella their task somewhat differs from that of their organelle doppelgangers. This structure is located outside the nucleus and usually is seen in pairs. The organelle consists of a cylindrical, nine-pointed star-shaped body, each point of the star connects to groups of three structures called microtubules. During Mitosis, the microtubules produce short spindle-fibers that move the chromosomes during cell division. These Fibers are supported by microtubule structures known as asters, the fibers extend from the centrioles to the cell membrane and move chromosomes to the daughter cell that is being created.

The size of our scale model is determined by calculating the ratio between the size of organelle and the size of our model.

Size of organelle = 0.2u D X 0.4u L = 0.00002cm X 0.00004cm

Size of model = 2.2cm X 4.4cm

ratio:

0.00002 : 2.2

simplifies to:

0.00001: 1.1

1. divided by 0.00002 = 110000 (model is 110000 times bigger than actual organelle)

The construction of the morphological model was conceived in a brilliant and sudden sketch that was then constructed in a very pleasant fashion, mostly of recycled materials. The design was fairly simple, strings tied through cups would be used to represent the actions of the centrioles. Until, that is we noticed that we weren't suppose to physically manipulate the model to make it work and our model worked by manually pulling the strings to move the organelle. It was obvious that we needed some sort of electromotive device to do the action for us. Luckily Gunther has motors and gearboxes just laying around so we taped a motor to the back of the model and soldered wires, a switch and a battery to create a working circuit. Then we attached the motor's axle to the strings to wind them up rather than having a person pull them.

In the construction of the scale model, it was difficult getting the play doh to stick to the platform but I overcame that issue with duct tape. Also I needed a way to make it easy to see that there are nine separate triplets of microtubules so I used different colored play doh to make it easier to see that. And the function of them is to form spindle fibers to separate chromosomes during cell division.

Torque Lab

Hypothesis:

In a system of parallel forces at equilibrium the sum of the counterclockwise torques is equal to the sum of the counterclockwise direction.

Procedure:

The mass of a meter stick and the mass of a weight were measured and recorded. Then an axil was attached that allowed the meterstick to placed on a stand. The position of the fulcrum was adjusted until the meter stick was horizontally balanced on the stand. The location of the fulcrum was then recorde. next we changed the location of the fulcrum to 60 cm and placed the weight over the shorter side. The distance of the weight from the fulcrum was then adjusted until the meter stick was horizontally balanced. The new position of the fulcrum was then recorded.

Data:

Meterstick CG: 49.9cm

Meterstick mass: 39.3g

Meterstick weight (hundredth of a Newton): .91N

Equilibrium position of unknown mass: 79.9cm

Unknown mass: 47.5g

Unknown weight: (hundredth of a Newton): .47N

Data Analysis:

Error Analysis:

(.46 - .47) / .47 = -.02       =        2% Error

Conclusion:

We found within 2% error that the sum parallel forces at equilibrium is equal to the sum of the counterclockwise torques is equal to the sum of the counterclockwise direction within a system.

Cellular Energy Essay

The semi-permeable membrane of a cell's membrane is a highly selective barrier. A cell membrane uses a combination of diffusion, osmosis, facilitated diffusion, and active transport to move materials in or out of the cell in order to maintain proper concentrations on both sides of the membrane.  Diffusion is the movement of materials from an area of greater concentration to an area of lower concentration until equilibrium is reached. Osmosis is the same as diffusion accept with water. Facilitated diffusion occurs in living cells only and is used to transport matter in through the cell membrane that is either to large to diffuse or is charged. Facilitated diffusion moves materials through an integrin transport protein from an area of higher concentration to an area of lower concentration. Active transport requires ATP. Active transport moves materials from an area of lower concentration to an area higher concentration (against the concentration gradient).

Energy is the capability of something to do work. Work is to move matter in a direction it would not normally go in when left alone. There are two groups that different forms of energy fall into; energy is either potential or kinetic. Potential energy is energy that is stored. It has the capacity to preform work as a result of location or arrangement. An example of potential energy would be the energy that is stored in the molecular bonds of the molecule ATP. Kinetic energy is the energy of motion. Moving molecules or atoms have kinetic energy. An increase in thermal energy would mean that the molecular movement of a substance has increased. A covalent bond is when electrons are shared between atoms to make a total of eight in the outer shell. The amount of energy that it takes to form covalent bonds is exactly the same as the energy needed to break the bond. Part of the energy that is stored in these bonds is based on the two atoms that are bonded. If one atom has a very high electronegativity and the other has a very low electronegativity, than the bond that forms between these two atoms will have a higher potential energy. If the electronegativity is about the same the potential energy stored in the covalent bond will be lower. Going back to the example of ATP as potential energy, the three phosphates bond's contain the primary energy in the ATP molecule. When cells use ATP energy is released from the bonds when a phosphate group is broken off.

The best way I learned about diffusion and osmosis was the lab that was conducted in class with dialysis tubing. I thought it was very interesting how diffusion and osmosis directly affect each other. When glucose diffused into the dialysis tubing it caused the water to leave the tubing through osmosis. It was also interesting to see that the starch which could not diffuse through the tubing did not affect the glucose diffusing or the water in osmosis. The concept of proving that one molecule is larger than the other seemed difficult to achieve at first but the data that was produced accurately supported the hypothesis that had been created.

I learned the most about energy in covalent bonds from my notes on energy that were taken in class. They provided accurate and straight to the point facts that were very useful because I was able to link them to what I had already learned about covalent bonds. I also had a lot of prior knowledge on energy forms from personal research that I had done previously after reading an article on perpetual energy devices.

The knowledge that I have acquired during this unit of study has helped me to clearly understand how energy moves naturally and how everything either is or requires energy in order to do something (work). Going beyond the information that was learned for this unit, I also learned more about problem solving and figuring things out based on what information is given. The dialysis lab was the origin of this development. During the lab, there were a few points where I felt as though I was on the wrong track or something was not working right but when I looked at all of the information that was collected from the experiment together I realized what it meant. This unit will help me to be more successful in the future not only from the information but also from the experience of learning it.

Atomic Structure Essay

The atomic number of a given element defines the identity of that element. The atomic number is equal to the number of protons in an atom. The amount of protons in an atom is fixed and cannot change without changing what element it is an atom of. The atomic mass is a sum of the number of protons and neutrons in an atom. To figure out how many neutrons in an atom, subtract the atomic mass from the atomic number. The atomic mass is not fixed because an atom can gain or give up electrons. An atom has the same number of electrons as protons. However, as previously mentioned, the number of electrons that an atom has can change. When an atom gains or loses electrons it becomes an ion. An ion is a charged atom. Ions have a different number of electrons than normally expected in the atom of that particular element. An ion is either positively charged (cation) or negatively charged (anion). A cation has less electrons than protons and therefore, because protons have a positive charge, the ion has a positive charge. A anion has more electrons than protons and therefore, because electrons have a negative charge, the ion is more negative. Protons have a positive charge, neutrons have a neutral charge and electrons have a negative charge. An isotope is an atom that has the same number of protons as another atom of the same element but has a different number of neutrons. These two atoms are still the same type of element, only the one with a different number of neutrons than expected is an isotope. Isotopes can either have more neutrons or less neutrons than the atom is expected.

Everything on the periodic table that is located to the left of the staircase is a metal, everything to the right of the staircase is a nonmetal. Elements group on the periodic table from a variety of properties. The Atomic numbers' and atomic masses of elements on the periodic table increase from left to right and from top to bottom. The number of orbitals increases from left to right and is determined by subtracting 10 from the element's group number. Electronegativity increases from left to right and decreases from top to bottom on the periodic table, however, the noble gases do not follow this pattern. Atomic size decreases from left to right and increases from top to bottom. The atomic size does this because the more electronegativity an atom has, the closer its electrons are pulled in towards the nucleus.

Electronegativity is the ability of an atom to gain and hold onto an electron. Atoms with the most electronegativity have more valence electrons and less rings. Electronegativity increases from left to right and decreases from top to bottom. The more rings an atom has, the further the valence electrons will be from the center of the atom and therefore the less the atom will be able to attract them in closer to its nucleus, this is why electronegativity decreases from top to bottom. Atoms have difficulty holding onto electrons the further the electrons get away from the nucleus. Electronegativity increases from left to right because the amount of valence electrons that atoms have in each group also increases from left to right. Atoms that are more electronegative have more valence electrons and fewer atomic shells, or orbitals. Florine is the most electronegative element.

The Octet Rule is the property of atoms to seek either two or eight electrons. The alkali metals all have one valence electron and naturally wants to give that valence electron away in order to have eight electrons in the outer shell. Nonmetals want to receive electrons in order to have eight valence electrons. In a non-polar-covalent bond, atoms share eight electrons in their outer shell. In polar covalent bonds, the electrons spend more time around the larger molecule there fore the end with the larger molecule has a negative polarity. Ionic bonds form when one or more electron from an atom move to another atom in order to satisfy the octet rule.

Nearly all of the above was taught in class and recorded in my notes, but the most effective tool for learning it was the periodic table assignment where it was instructed to label trends in the periodic table. I had been planning on studying in a similar way and ended up including more information on the back than the assignment required. By using my notes and looking up anything that I didn't understand on the Internet, I gained a very thorough understanding of the topic. When I finished labeling trends and adding notes to the back, I felt as though I could still add a lot more information. This told me that I had learned the material well. At first, the concept of electronegativity was difficult for me, so when I went home with a free-write assignment on the topic I had to make sure I had a good understanding of the subject, otherwise I would be unable to accurately complete the assignment. I watched several videos on youtube about electronegativity which ended up being a great help. Each video was slightly different and each had information that the others lacked, so between repetition and the presentation of new information, I was able to clarify and gain a full understanding of electronegativity. I have used this technique many times since and have found it to be extremely helpful because I will often think of questions after I leave class that I would have liked to have known the answer to. All of these learning strategies have truly helped me to connect the notes and handouts from class to gain a better understanding of electronegativity and the many other topics that I have learned about in this unit.

How atoms behave, how they bond and why they bond is an extremely important for understanding how and why everything happens or will happen. Starting with the smallest known unit of matter is probably the best way to begin learning about something. As you build on those smaller units, you begin to see emergent properties that were not present at a smaller level. For example, the atoms of hydrogen or oxygen in a water molecule have no special properties on their own, but when they have a polar covalent bond, they now express the characteristics of adhesion and cohesion. As demonstrated by this example, every aspect of atomic actions, bonds and trends gives other materials and reactions that we deal with every day, their properties. Electronegativity is responsible for the occurrence of every chemical reaction that occurs and is therefore very important for understanding how anything happens down to its simplest level of existence. Another important connection is the link that I often find between what I have done in class and my daily activities of another class. For instance, this semester I am taking Electronics II. It is convenient that at the same time I was learning about charges (ions) in electric circuits, we talked about ions that same day in Biology. I was really glad because a lot of times, the things that you learn in one class have no reverence to anything else in any other class. I felt like I had a good grip on the subject because I was able to use recently acquired knowledge to my advantage.

Biology Math Essay

pH is the acidity or base of a substance that is dissolved in water. The pH of a substance is based on the number of H+ and OH- (Hydrogen ion concentration) the solution has. If there is more H+ than OH-, the solution is acidic. If there is more  OH- than H+, the solution is basic. The scale on which pH is measured is from 0 (lowest pH) to 14 (highest pH). The number 7 represents neutral pH. Water has a neutral pH. This means that there is an equal number of H+ and OH- in water. A log is the exponent of how many exponents the pH is measured as. For instance, a pH of 3 represents a -log which is is equal to 10-3. This means that a substance with a pH of 4 has a concentration of hydrogen atoms that is 10 times greater than a substance with a pH of 5. The pH of the human body that is  is usually between 7.35 and 7.45, this is because our body has buffers, natural protectors that can tolerate acids which is important because there are many acids that are produced regularly by the body. Stomach acid has a pH of 2. The formula pH = -log (H+) is important to understanding pH. The (H+) part f the formula represents the value of the pH of the solution in scientific notation,  for example, a pH of 2 is the equivalent of 10-2. A commonly used acid is hydrochloric acid. If you mix an acid with a base, you can create a more neutral substance by making the H+ and OH- ions equal, or at least closer to equal, in concentration.

To convert between metric locate the prefix of given quantity. Then take the number associated with that prefix and move the decimal either forwards or backwards to the desired decimal prefix. If there is no prefix, the unit is in its base measurement. A base measurement is, for instance, a unit such as 12 M or 6 K. For example, 3 grams converts to an equal measurement of 0.003 centigrams. Zeros are added as necessary, as place holders, but they do not have any significance because they will be created or eliminated when converting between units of measurement.

Learning the concept of pH was slightly confusing at first when discussing it in class. The notes taken on it were extremely helpful. There was a key point near the middle of the notes where the arrows were drawn where I made the connection between the acid and the base on either side of the neutral seven. I understood the concept of metric conversion, the only problem I had with it was remembering the order of the prefixes. To remember them easier, I made an acronym using the first letter of every prefix. The most helpful resource for learning this was the no-think metric conversion latter handout that was distributed in class.

The information that I have acquired during unit 1 of this biological study has helped me to realize how much mathematics really is connected to biology and everything we use in our every day lives. Comparing metric measurements with different unit prefixes would be impossible if one was unable to convert them to the same unit of measurement. It is very important to know the difference between a acid and a base and to be able to tell what the pH of a solution is when only given a number because about half of the lab experiments that we have done in this unit have involved acids and bases.

Human Body Analytical Essay

The first portion of the digestive track is called the alimentary canal. It is the first part of the complicated process of digesting food. The alimentary canal consists mainly of the esophagus, large intestine, small intestine, oral cavity, pharynx and stomach. Though other organs are also involved in the process such as the tongue, teeth, pancreas, and gallbladder. Peristalsis is the primary rhythmic muscular movement that moves food through the alimentary canal. The teeth are the first means of mechanical digestion. Humans have four types of teeth incisors, canines, bicuspids, and molars.

Chemical digestion starts in the mouth where enzymes like amylase that digests starch begin to break down food. Food travels to the cardiac sphincter that opens and allows the food to pass into the stomach. The stomach contains acid that has a pH of 2. Gastric juices are secreted from gastric pits in the stomach. Mucus cells produce a thick coating called mucus that lines the interior of the stomach and lubricates it as well but most importantly it protects the stomach lining from the strong acids that it produces. Cells called chief cells make a chemical called pepsin. Pepsin breaks down protein. When the food is broken down it enters the duodenum. The duodenum is the first section of the large intestine. Here, most of the chemical digestion that occurs in the body happens. The gallbladder produces a substance called bile that neutralizes acid. The pH in the large intestine becomes a 7 (NEUTRAL). Carbs are digested in the small intestine along with proteins that were not broken down in the stomach. Pancreatic juice aids in the breakdown of macromolecules. Absorption begins in the small intestine. Food continues into the small intestine where food is absorbed and water is regained by the body. Feces is stored in the rectum until it can be released.

For me the best tool for learning this material was to draw out all of the organs and then to label them with color and their names and what they do. I drew a large three page portrait of the digestive system that was correctly labeled and only had two errors that I realized I had made when I was done. I switched the places of the large and small intestine and put the pancreas in the wrong spot. To me all of this knowledge that I acquired in this thematic unit of study shows not how the rest of the world works,  but how we work. It is interesting to study because people often separate humans from the rest of the animal kingdom when they really are a part of it.

Photosynthesis Analytical Essay

Photosynthesis is a plants way to produce the glucose that it needs for cellular respiration because plants do not get the energy that they need from food, they have to make it by transforming carbon dioxide and water into glucose water and molecular oxygen. The formula for this is:

6CO2 + 12H2O → C6H12O6 + 6H2O +6O2

Photosynthesis is a redox reaction, in other words, the reduction of carbon dioxide into sugars and the oxidation of water into molecular oxygen. Oxidation reduction reactions or redox reaction occur when there is loss of electrons equates with oxidation and gain of electrons equates with reduction. Electrons will move from one atom to another.

Cellular respiration is occurs simultaneously with photosynthesis in plants but is almost the complete opposite. Cellular respiration turns glucose into energy while photosynthesis turns energy, water and carbon into glucose. Photosynthesis takes advantage of the energy in light using photosystem II and photosystem I. Photosystem II is first in this process but I named otherwise because it was discovered second. First is the Calvin cycle. The process of turning light into energy begins when light in the form of a photon hits the reaction center of photosystem II in the thylakoid in a chloroplast. Cellular respiration on the other hand, begins in one of three stages. Cellular respiration begins with glycolysis, the splitting of glucose that occurs in the cytosol. First glucose is split into two 3 carbon sugars. Then oxidized into two molecules of pyruvate. NAD+ is reduced to NADH in the process. Two molecules of ATP are used to lower the energy of activation. Four ATP are produced as the bonds are broken and form because of phosphate level phosphorylation. Next is what is called the intermediate step. This occurs in the mitochondrial matrix. Oxygen is required for this process to occur. First the 3 carbon pyruvate enters the mitochondrial matrix via active transport. The carbon compound is oxidized, reducing NAD+ to NADH forming a 2 carbon acetyl molecule that then bonds to coenzyme A. Then in krebs cycle also known as the citric acid cycle, acetyl coenzyme A bonds to a 4 carbon acetyl molecule. Coenzyme A is then released and recycled back into the intermediate step. During this process 3NAD+ is reduced to 3 NADH and 1FADH is reduced to FADH2. One ATP is made and 2CO2 is released. The krebs cycle occurs twice for one molecule of glucose because 1 molecule of glucose produces 2 pyruvate and is mainly the process to get rid of CO2.

The best way for me to learn this material was an input output chart I made for cellular respiration. This helped me to remember what materials went in and turned into what. It was easiest just to remember the input such as if I knew that one NAD+ went in I could easily tell that one NADH would come out. For photosynthesis the best thing for me was a picture in a packet that was given out in class that featured an illustration of photosystem II and photosystem I with arrows showing the flow of energy and products in the reaction. To me this all is the explanation of why we really need oxygen and why we exhale carbon dioxide. This whole unit has brought together for me a better understanding of the near symbiotic relationship between plants and animals. Carbon dioxide and water and sunlight  to glucose, water and oxygen to carbon dioxide again... All life lives together.

Portfolio Essay Genetics

DNA and RNA are abbreviations for deoxyribose and ribose nucleic acids. DNA and RNA are polypeptides composed of long chains of nucleotide monomers. These nucleic acids are polymers that serve as the blueprints for constructing proteins. Their monomers are called nucleotides. There are five kinds of nucleotides, each is made of a five-carbon sugar, a phosphate group, and one nitrogenous base. The five kinds of nucleotides are; adenine, guanine, cytosine, thymine, and uracil. However, thymine is only found in DNA and uracil is only found in RNA. A polynucleotide is formed when dehydration synthesis occurs between one nucleotide and the sugar of another. This results in a repeating S - P backbone. DNA is double-stranded (double-helix) RNA is single stranded. Despite the different number of strands and the difference of uracil in RNA, DNA and RNA have virtually the same structure. The both have a sugar-phosphate backbone, and nitrogenous bases. In DNA, the base pairs are complementary so that the DNA is even in diameter all the way down its length. The complimentary nitrogenous bases pair as follows: guanine only bonds to cytosine and thymine only binds to adenine accept uracil replaces thymine in RNA. Uracil replaces thymine because uracil takes less energy to make, but is not as stable.

DNA replication is a complicated process that is dependent on specific base pairing. The Central Paradigm is what some call the conversion process from DNA to RNA to Protein. Genetic information is written as codons. Codons are groups of three nitrogenous bases. The information that is stored on a DNA molecule needs to be used to create proteins. DNA cannot leave the nucleus in eukaryotic organisms because the molecule is to large to move through the nuclear membrane. There is 20 amino acids and 4 base pairs. The process of transcription is the making of Messenger RNA (mRNA) off of the DNA molecule. Transcription occurs when information that is stored in the base sequences of DNA is transcribed to make single-strand of messenger RNA (mRNA). In other words, the DNA's code is rewritten as mRNA. The mRNA molecule is made from just one of the strands of the DNA molecule because the other side is used to produce transfer RNA (tRNA). The mRNA is able to leave the nucleus so that it can create the necessary proteins in the cytosol. The mRNA is complementary to the section of DNA it was copied from accept for how it has uracil instead of thymine. DNA  is essentially the template for creating the proteins that the cell needs to grow, function and survive. The RNA nucleotides are linked by transcription enzyme called RNA Polymerase. RNA polymerase must be told where to start and where to stop the transcribing process. The start signal is the promoter area of DNA, the promoter is a sequence of bases called a TATA box. TAC is the 'start' codon which sets the triplet code. The first phase of transcription is triggered when a specific hormone or signal protein enters the nucleus as a message that a specific protein section of the DNA is needed. The enzyme RNA polymerase attaches to the promoter of DNA. For any gene, the promoter region signals only one of the two strands to be transcribed. This is the lead strand of DNA, this is where mRNA are made. The other strand of DNA is the lag strand, where tRNA is made. RNA elongates as RNA polymerase assembles it in sequence complimentary to DNA. Finally RNA polymerase reaches a section on the DNA lead strand called the terminator. The terminator signals the end of the gene and causes the RNA polymerase to detach. The DNA strand reforms a double helix and the mRNA is released. Genetic messages are translated in the Cytoplasm. Messenger RNA conveys the genetic information from DNA in the nucleus to the translation devices in the cell's cytoplasm. The mRNA and tRNA leaves  the nucleus and enters the cytoplasm if the organism is a eukaryote, if the organism is a prokaryote, the mRNA simply stays in the cytoplasm where it is because prokaryotic organisms have no nuclear membrane or nucleus to contain their cell's DNA. The tRNA is a molecular interpreter that translates base sequences to a proper amino acid. In living cells, amino acids are either synthesized or obtained from food. The tRNA picks up the appropriate amino acid and then recognizes the appropriate mRNA codon to place the amino acids in the right sequence.

One of the difficulties that I had at first with DNA replication was that not all of the DNA is used to produce a single protein, but once I realized the part about the start and stop codon meant that there could be multiple start and stop codons on a single DNA strand, it all became clear to me. The best tool for learning DNA transcription and translation were videos on the internet. They were the largest help for me to learn about this topic because I was able to hear what the molecules were and what they do as I watched them do it. The only bad thing about the videos was that most of them had different animation where some had molecule-looking models and others had symbolic shapes for each molecule and organelle.

The knowledge that I acquired during this thematic area of study such as the structure of DNA reveals many things about the biological world that we live in and study. It shows how organisms are able to grow and reproduce – key aspects in determining whether or not a chemical reaction is alive or not, because in reality, that is all that life is.

URLs of helpful internet videos:

http://www.youtube.com/watch?v=vJSmZ3DsntU

http://www.youtube.com/watch?v=WsofH466lqk

http://www.youtube.com/watch?v=983lhh20rGY

http://www.youtube.com/watch?v=41_Ne5mS2ls

Evolution Book Response

When choosing a book for this assignment, I immediately knew that I wanted to read something on evolution. My first thought was to go with The Origin of Species, by Charles Darwin, whose name is used almost synonymously with the theory of evolution. However, after discussing my choice with several people who had previously read the book, I was informed that the content of the book was somewhat or according to some, “unfathomably dull”. Based on this general consensus I now looked for a new source to for fill my lust for a book on the subject of the change of species over time.

I decided to check in the school's library for anything that might match the criteria of what I was looking for. In my search I came across the book: From Ape to Adam by Herbert Wendt (published 1972). Since I knew the bell would ring soon, I decided to check the book out. Later at home I began reading the first few chapters; this was the book I was looking for. I found this book very appealing because it was not just about how evolution occurred, but about how the theory of evolution evolved. This book does not focus its efforts on how evolution began with the creation of a common ancestor of all living things because even today, scientists are still unsure as to the answer. Instead it shows the struggle of how one species attempts to understand how it came into existence. This book really made me think about who I am and how much it has taken to make me exist. I'm Gunther and I'm the result of over 6 million years of events. This thought inspired by what I read and the class notes on the law of conservation of matter and energy made me imagine where the atoms and particles that I am made out of have been before I ever existed, that every part of me and everyone else originated from the same source at the beginning of time. This scientifically based statement seems to pull the worlds of religion and science closer together than many may think possible.

What immediately drew my interest was the parts that theorized the origins of ancient myths such as the mythical creatures called gorgons based on what is believed to be some of the first recorded evidence of modern man's interaction with his closest living ancestors. These meetings of two species with the same genetic narrative are proof that modern man did not evolve in a straight sequence of events where a new species emerged as the old one died out. More likely it was that modern man existed alongside those with the genetic code that he had evolved from. With the two species competing for resources, modern man was more efficient than his primitive neighbor and out competed him.

Besides what has been previously mentioned, this book discusses not only what the current theory of evolution is but every major step that contributed or dis-contributed to the current understanding of how modern man came to be. As with most older scientific debates, religion made the subject of evolution very controversial. Fearing criticism, few were bold enough to stand before an audience to discuss the ancestors of man. Many people openly mocked anyone who claimed that man evolved from a primitive ancestor. This was very similar to the situation with Galileo who claimed that the earth orbited the sun and was not the center of the solar system.

Proof such as ancient tools like arrowheads and stone hatchets were regarded as mere coincidence, chipped rocks that just so happened to resemble a primitive tool, just a natural phenomenon. Cave paintings discovered all across Europe were said to be only the practices of a local artist who had expressed his talent in the cave. It wasn't until later that the important discovery was made, of human-like bones along with the bones of other animals, charcoal, and various stone tools were found in caves, fossilized under layers of limestone. Later many cave paintings were authenticated when it was discovered that some if the images painted on the walls extended below the layers of limestone that made up the cave fore. This proved that these artifacts were indeed authentic since it would have taken over a thousand years for the limestone to form in that thickness. Later, early human remains were discovered all over Europe alongside the tools they had used and remains of the animals they had eaten. After these discoveries, most of the scientific community began to look closer into previously discovered artifacts and art. From closer observations, they were able to determine that ancient humans had a fairly developed culture that included art, ceremonial rite of passage from child to adult, and burial rituals for the dead.