Monday, November 15, 2010

Eggs Lab

The Eggs Lab
                                                                                                            Olivia Jacobs
                                                                                                              Ellie Hogg

  1. Introduction

One of the most important parts of cell is the semi permeable cell membrane. The cell membrane, commonly known as the plasma membrane, allows small polar molecules to pass through it while larger molecules cannot. This process is called active transport. Molecules will move through the cell membrane according to the concentration gradient (the difference in concentration of a substance from one location to another) from a hypertonic environment (an environment where there is a higher concentration of dissolved particles than a cell) to a hypotonic environment (an environment where there is a lower concentration of dissolved particles than a cell) which means that the molecules require no energy from the cell to pass through the plasma membrane. How does the concentration gradient determine the direction the molecules will move through the cell membrane? How do a hypotonic and a hypertonic environment differ?

2. Hypothesis
           
If one egg that has been soaked in vinegar is placed in a cup, half full of distilled water and one egg that has also been soaked in vinegar is placed in a cup of corn syrup, then the egg in distilled water will swell and the egg in corn syrup will become softer and more paper like, thinner outside layer.

3. Materials

Used in this lab were 2 foam cups, approximately three fourths cups of    distilled water, approximately three fourths cups of corn syrup, a scale, a tape measure, four paper towels, and two eggs bathed in vinegar.

4. Procedure

Day 1- The eggs were removed from the vinegar bath and dried using paper towels. The eggs were measured around the horizontal middle and the weight was taken in grams. This data was recorded. The first egg was placed in a foam cup half filled with distilled water and the cup was labeled with a ‘W’ for water and a number ‘1’. The other egg was placed in a foam cup half full of corn syrup and the cup was labeled with a ‘CS’ for corn syrup and a number a ‘2’. The cups were moved to a lab station out of the way, the paper towels were thrown away and the tape measure was replaced.
Day 2- After the eggs were left in the cups for 72 hours they were removed and dried using paper towels. The eggs were again measured using the tape measure and the scale (in grams). Data was recorded and the paper towels as well as the cups were thrown away. The eggs were observed and observations were recorded. Then the eggs were also disposed of.

5. Data and Observations
The egg that was placed in the distilled water swelled slightly after twenty minutes in the cup. After 72 hours, however, the egg had a small hole in it and had returned to its original size. The egg that had been placed in corn syrup had shrunk and the shell was translucent in some places. There were dents in the shell and when rolled on a paper towel, the egg flattened slightly and left a chalky, yellowish- white residue on the paper towel.
Graph number one describes the size and appearance of the egg that had been in distilled water before and after the egg had been place in the water. Graph two describes the size and appearance of the egg that had been soaked in corn syrup both before and after it had been placed in the cup. Graph three represents the change in size of the eggs according to how long they were left in the corn syrup and water by the whole class. Each group (1-10) recorded the data on this graph.
6. Error Analysis
                        During the experiment, after the eggs had been placed in the cups and moved to the lab station, it was realized that the weight of the eggs before the experiment had not been taken. It was too late to measure the weight of the eggs. Next time, in order to make more accurate quantitative observations, we should pay more attention and be more aware of instructions.

7. Results
               Egg Osmosis Lab Analysis Questions
1.      When the egg was placed in the water, in which direction did the water molecules move? The polar water molecules moved from the hypotonic environment of the water through the egg shell into the egg.
2.      On what evidence to you base this?  Based this on the evidence that the egg was slightly larger than it began after soaking in the water, I concluded that some of the water must have moved through the semi permeable egg shell into the egg.
3.      How do you explain the volume of liquid remaining when the egg was removed from the syrup? It appeared that there was more liquid in the cup but that the syrup was much thinner and seemed watered down. This may be because the water within the egg moved through the semi permeable egg shell out of the egg where there was a lower concentration of solvent and a higher concentration of solutes.
4.      Why did the water molecules travel better inside the cell than the syrup molecules? The water molecules may have moved better inside the cell because the outermost layer of the semi permeable membrane has polarity. The water molecules are also polar which would mean the water would be attracted to the semi permeable membrane, and would pass through it. Also, the water molecules are much smaller than the particles that make up the syrup which makes it easier for them to pass through the membrane.
5.      What is the purpose of placing the egg in the vinegar? The egg was placed in the slightly acidic vinegar so that it would eat away at the outermost layer of the calcium carbonate shell leaving only the cell membrane of the egg which is the part of the egg that we want to observe.
6.      Did your results match the results found in the rest of the class? Why? Our eggs showed similar changes to those of the rest of the class. For the most parts, our results were more exaggerated because we left our eggs in the cups for a much longer amount of time (72 hours).
  1. Conclusion
The egg that had been placed in the cup of water swelled very slightly after soaking for 72 hours. This is because the concentration of solvent within the egg was much lower than the concentration outside the egg. The water molecules moved across the semi permeable egg membrane into the egg. The polar water molecules were attracted to the polar tops of the phospholipids that make up the plasma membrane. The egg that had been soaked in corn syrup shrunk quite a bit. This is because there was a higher concentration of solvent inside the egg cell. In my hypothesis, I stated that the egg that would be soaked in water would swell and that the egg in corn syrup would shrink and become more paper- like as well as thinner. My hypothesis was supported. What occurred in the cup of water was osmosis. Osmosis is the movement of water molecules across a semi permeable membrane from an area of higher concentration to an area of lower concentration. Osmosis also occurred in the corn syrup cup but the significance of the corn syrup was to represent selective permeability of the cell membrane as well as osmosis. It was visible that the water molecules from with in the egg cell were able to leave the cell through the cell membrane but the particles of corn syrup were unable to pass through the membrane into the cell.

I thought this lab was very effective and changes to the procedure might make it less so. 

Wednesday, November 10, 2010

Plasma Membrane

This week we've been working on understanding the fuction of a plasma or cell membrane. We've been made to draw diagams and label all parts of a cell membane. Mr. Twiggs had us stand together  and create a human plasma membrane. At this point, I think I quite understand the properties of a cell membrane as well as the functions. Overall our student teacher, Mr. Twiggs has much imroved in his teaching style as well as the way he handles students. His biggest issue, in my opinion is the obvious joy he feels in telling people what to do and how pejorative he is to his students.

Thursday, November 4, 2010

Cells

This month in Biology, we have been extremely focused on cells. We've drawn diagrams of cells, cell parts, organelles, different types of cells, and other cell related things as well as making graphic organizers and study charts, models and papers considering and analyzing cells and cell parts. I've been having dreams about cells, I've been making references to cells in completely unrelated classes.

Thursday, October 21, 2010

Lab Data and Observations/ Error Analysis

6. Error Analysis


In the lab Much Color Ado About Nothing, the wrong amounts of of oil and water were used in the graduated cylinders. Although this would not change the effects of the polarity between the water, food coloring, and oil, the experiment was redone using proper amounts before our data was recorded.

Also, in the Antigravity lab, not enough paper towel was used for the towel to retain a cylindrical shape and it fell down into the water. Before the experiment proceeded, a new cylinder of paper towel was made and the experiment was revised.



5. Data and Observations



Looney Balloony- When the balloon was placed near the stream of water, the steady stream of water was bent towards the balloon. As the balloon moved, the stream of water followed it.



Dish and Clips- When the paper clips were carefully placed in the water they floated along the surface. If not placed at the proper angle and very carefully, the paper clips would sink.



Stir it Up- When the stirring rod was turned at a diagonal, and at a certain angle, the water, would flow along the stirring rod and not drip onto the table. Almost all of the water poured along the rod successfully into the beaker.



Stop on a Dime- The dime held up o thirty nine drops of water with out spilling over. When the number of drops reached forty, they began to run over the edges of the dime, one at a time so that thee dime retained most of the water and a dome shaped bubble stayed on the dime’s face.



Much Color Ado About Nothing- The food coloring mixed with the water and turned it a light pink color. (The food coloring was red.) The coloring did not mix with the oil, however, it remained in drops and sunk to the bottom of the test tube. The oil did not change color.



To Wax Philosophic- The puddle of water tat was dropped on the wax paper stayed entirely together but became oblong as it was pulled along the paper. At one point, the drop split in two but quickly, the drops slid back together to reform the original bubble.



Antigravity- The roll of paper towel remained standing up right in the shallow dish of water while the water soaked upwards into the paper towel against gravity. Once the water had raised a few inches into the paper towel, the bottom was weak and heavy with water. This made the towel fall.

Wednesday, October 20, 2010

Lab Report rewrite

William Spencer


Ellie Hogg

Topher Robinson

Olivia Jacobs



September 18, 2010



Watered Down Puns



1. Introduction

Water is a universal solvent and a basic necessity for all forms of life. Water also has many properties that affect the way it behaves under certain circumstances. Some of these properties are adhesion, cohesion, surface tension, capillary action, and polarity (hydrogen bonds). Adhesion can be described as attraction between molecules of the same substance. Surface tension is very like cohesion in that it is related to the effects of water bonding with itself and other molecules. Capillary action is the ability of water to travel against gravity by means of adhesion and cohesion. Polarity is when an atom has a positive and negative charge and is therefore attracted to other charged molecules. These are properties of water that we will be exploring in our labs, and the ones that make water such a unique compound. This leads us to ask; Under what circumstances will these properties be exhibited.



2. Hypotheses

To Wax Philosophic-

If the disposable pipette is used to pull the water droplet around on the wax paper, then the drop will remain in a dome shape and all the water molecules will stay together instead of being separated.







Stir it Up-

If the water is slowly poured down a stirring rod that sits at approximately 40 degree angle inside the mouth of a graduated cylinder, then the water will flow down the rod and into the graduated cylinder without spilling or dripping from the rod.

Antigravity-

If the paper towel is made into a vertical cylinder and set in a metal pan of shallow water, the water will absorb upward into the paper towel, rising against gravity.

Much Color Ado About Nothing-

If the dropper is used to drop red food coloring into both a test tube containing 5ml of water and a test tube containing 5ml of an unknown oil, then the coloring will, in water, dissolve, changing the color of the water to red, and , in oil, the drops will float on top of the oil and remain in droplet form.

Stop on Dime-

If water is slowly dropped onto the face of a dime, approximately 30 drops of water will stay on the dime’s face before the water spills over the edge.

Dish and Clips-

If the forceps are used to place the metal paper clip on the surface of water in a small dish, then the paper clip will sink.

Looney Balloony-

If the balloon is rubbed with a paper towel and placed near a running stream of tap water, then the water will move towards the balloon and flow over it.

Thursday, October 14, 2010

Gerber Baby Food

Last week we began a project where we tested for the presence of certain chemicals in Gerber Baby Food Infant Meals. We found some pretty astonishing things and decided to write letters to Gerber describing what we found. Here is mine.

3 Pirate Parkway


Berea KY, 40403





October 12, 2010



START HEALTHY, STAY HEALTHY™ Resource Center

445 State St.

Fremont, MI 49413-0001



Dear START HEALTHY, STAY HEALTHY resource center,



It has come to the attention of the sophomores at Berea Community High School in Kentucky that some of the chemicals found in your baby food do not meet the nutritional value standards of most parents. We are worried that your customers are unaware of the presence of and effects of some of these chemicals found in your baby food. Infant nutrition is a serious concern among most parents, especially in a nation where obesity rates are higher than they have ever been in the United States.



We used a series of solutions that, when added to your baby food, changed the color of the product. The color change indicated the presence of polymers and the lack there of other important nutrients such as proteins and amino acids. Some of the chemicals detected in your product are large amounts of monosaccharide, (simple sugars), and disaccharides (complex sugars) that can seriously injure a baby’s health and lead to consequences later in life. Not only that, but the presence of polysaccharides (starches) and carbohydrates were extremely prevalent in your “healthy” infant meals over other important nutrients for child development.



Some of the foods we tested were bananas, mixed chicken and vegetables, peas, and potatoes. We found that in infant meals such as mixed chicken and vegetables, there was an astonishing lack of protein and in meals such as sweet potatoes, there was an over abundance of carbohydrates and starches. It is common knowledge that these things are detrimental to the health of average people, and therefore utterly destructive to the health of developing bodies as well as developing brains.



For a company whose motto is “START HEALTHY, STAY HEALTHY”, it appears that the health of your consumers is not a priority, but an option. We, the students of Berea Community School, suggest you make a few improvements in order to benefit the health of countless babies in America. Another option might be to make it clear to your customers that the food you are selling them is not of quality, but processed and lacking in vital nutrients. We suggest that you instigate these changes immediately or to somehow make amends with the thousands of babies who are already experiencing the negative effects of Gerber baby food.



Sincerely,











Olivia C. R. Jacobs

Tuesday, September 21, 2010

Lab Report two

       Olivia Jacobs
            Ellie Hogg   
  William Spencer
             Topher Robinson

                                                                                                           

                                                          Watered Down Puns

1. Introduction

            Water is the universal solvent and a basic necessity for all living things. Water also has many properties that affect the way it behaves under certain circumstances. Some of these are adhesion, cohesion, surface tension, capillary action, and polarity or hydrogen bonds. Adhesion can be described as the attraction among molecules of the same substance, while cohesion is the attraction of molecules of the same substance. Surface tension can be described as the affects of cohesion; otherwise the bonding of the water molecules on a surface. Capillary Action is the ability of water molecules to travel against gravity by adhesion. Polarity is the difference of charges in an H-Bond, creating a neutral molecule. These are the properties of water that we will be exploring in our labs and the ones that make water such a unique compound. Under what circumstances will these properties be exhibited?


2. Hypotheses

To Wax Philosophic-
            If the dropper is used to pull the water droplet around on the wax paper, then the drop will remain a dome shape and all the water molecules will stay together instead of separating or being absorbed.

Stir it Up-
            If the water is poured from the beaker slowly down the stirring rod, which is set at an angle, the water will flow down the rod and into the graduated cylinder without spilling or dripping from the rod.

Antigravity-
            If the paper towel is set in a vertical cylinder in the pan of shallow water, then the water will absorb upwards into the paper towel.

Much Color Ado About Nothing-
            If the dropper is used to drop food coloring into a test tube with 5 ml of water and color is dropped into 5 ml of oil, then the coloring will, in water, dissolve, changing the color of the water while, in oil, the drops will float on top of the oil and remain in drops.

Stop on a Dime-
            If water is slowly dripped from the dropper onto the face of a dime, approximately 35 drops of water will stay on the dime’s face before the water spills over.

Dish and Clips-
            If the tongs are used to place the paper clip on the surface of water in a small dish, then the paper clip will sink.


Looney Balloony-
            If we rub the balloon with paper towel and put it near a running stream of water, then the water will move towards the balloon and flow over it.



3. Materials

To Wax Philosophic- The materials we used for this lab were tap water, a water dropper, a  beaker of water, and a sheet of wax paper (roughly 1’ by 1’). 

Stir it Up- The materials we used for this lab were a glass stirring rod, a beaker of water, and a graduated cylinder.

Antigravity- The materials we used for this lab were a dish of water, and a paper towel.

Stop on a Dime- The materials we used for this lab were a beaker of water, a water dropper, and a dime.

Dish and Clips- The materials we used for this lab were a beaker of water, a shallow dish of water, a pair of tongs, and a paper clip.

4. Procedure

To Wax Philosophic- We, using the water dropper, put a drop approximately the size or a dime onto the wax paper. We used the tip of the dropper to pull the drop around in circles on the wax paper. The drop remained in a dome shape and stayed in one drop without separating even though, as we pulled it, it became oblong instead of circular.

Stir it Up- We angled the stirring rod in the graduated cylinder and rested it on the lip of the graduated cylinder. We then slowly poured the water from the beaker onto the stirring rod near the top. The water drained down the stirring rod into the graduated cylinder without spilling.

Antigravity- We rolled the paper towel into a cylinder and stood it vertically in the dish of water. The first time, the towel came unrolled and fell over, so we made a new cylinder using a larger sheet or towel. The second time, it stood and soaked up the water up to a few inches.

Much Color Ado About Nothing- We put color (3 drops), using the dropper, into a 5ml test tube of water. The color dissolved, changing the color of the water. We also put color drops (3 drops) into a 5ml test tube of oil. The water stayed in bubbles but sunk slowly to the bottom of the test tube.

Looney Balloony- We rubbed the balloon thoroughly with a paper towel. Then we moved the balloon close to a stream of water, from a tap. The water stream moved away from the balloon slightly.

Stop on a Dime- We slowly dropped small drips of water onto the center of the face of a dime. The water formed a bubble and as it grew, remained on the face of the dime until we dropped the 40th drop onto the dime. Some of the water then spilled over the edges of the dime.

Dish and Clips- We slowly placed the paper clip on the surface of the water horizontally. The first time, the clip sank because it was placed at an angle. The clip was horizontal and floated atop the water in the dish.

5. Data and Observations.
















































6. Error Analysis

In the lab Much Color Ado About Nothing, our group accidentally used the wrong amounts of oil and water. Before we recorded our data, however, we went back and redid the lab with the proper measurements. Also, in Antigravity, the paper towel roll was originally not thick enough to stay in a cylinder shape but we corrected that, also before recording our data by making a thicker roll.

7. Results and Analysis Questions

Antigravity- In antigravity lab, we observed cohesion adhesion, and capillary action occurring between the water molecules themselves as well as the water with the paper towel. This is why the water appeared to defy gravity. My hypothesis was supported.

To Wax Philosophic- We observed, in this lab, the affects of Adhesion. Because the water molecules had bonded to themselves, they pulled each other around without letting go. This is why the bubble did not split or separate. My hypothesis was refuted.

Stir it Up- This lab showed how adhesion takes place between molecules of different compounds. The water molecules boded to the glass and clung to it instead of spilling or dripping. My hypothesis was supported.

Much Color Ado About Nothing- In this lab, we observed properties of water density in comparison to oil and food coloring. My Hypothesis was refuted in that the color bubbles sank to the bottom of the oil instead of floating on top of them.

Looney Balloony- In Looney Balloony, we observed the effects of polarity. The opposing polarities of the water versus the balloon created an antimagnetic effect. My hypothesis was refuted.

Stop on a Dime- In Stop on a Dime, we watched as the effects of surface tension take place. The water was so tightly bonded with itself and the face of the dime that the water did not spill over until there was a large dome shaped bubble on the dime. My hypothesis was refuted as more water drops stayed on the dime than I suspected.

Dish and Clips- In Dish and Clips, we saw the effects of adhesion and cohesion. The clip floated on the water, by bonding with each other. The clip displaced very little water and did not sink. My hypothesis was refuted.


8. Conclusion

To Wax Philosophic- In To Wax philosophic, the water drop slid across the wax paper without splitting, braking, or separating into multiple bubbles as we pulled it with the tip of the water dropper. This occurred because of cohesion when the water molecules boded with each other. In my hypothesis, I said that the bubble would remain intact, as it did, due to surface tension, therefore my hypothesis was reported. If this lab is repeated, I suggest trying to use larger drops of water, or testing how large the drop can get and still retain its singular bubble shape.

Stir it Up- In this lab, the water that we poured down the stirring rod drained into the graduated cylinder without spilling or dripping due to adhesion. The glass and the water bonded with each other and the gravity caused the downward flow of the water. In my hypothesis, I thought that the water would keep its bond with the rod, which it did, therefore my hypothesis was supported. Although, if the lab is repeated, I would improve it by testing the angle the stirring rod is set at and seeing how close the rod can get to horizontal while still retaining its bond with the water.

Antigravity- When we placed the rolled up paper towel in the dish of water, the water absorbed upward into the paper towel until it was a few inches high and the towel fell over. This, I learned, is because of capillary action or a combination of cohesion and adhesion where that water bonds with itself and is absorbed into the towel. My hypothesis stated that the water would absorb into the paper towel, which it did.

Much Color Ado About Nothing- In the water, the color dissolved and turned the water a pinkish color. When the color was dropped into the oil, the drops slowly sank down to the bottom of the test tube. My hypothesis suggested that the drops of color would float on top of the oil because it was less dense. Apparently, the color was denser that the oil however, as it sank.  I would suggest using graduated cylinders instead of test tube because in the oil, the drops of color were forced to combine when they would have remained bubbles in a wider mouthed container.

Loony Balloony-The stream of water moved away from the balloon slightly because they had the same polarity after we rubbed the balloon with the towel. My hypothesis suggested that the water would be attracted to the balloon and was refuted.

Stop on a Dime- In this lab, the surface tension of the water caused it to stay on the face of the dime. The water was attracted to itself and held on even though it appeared that the water would spill over. In my hypothesis, I thought that 35 drops of water would stay on the dime’s face when forty drops were sable to stay on the dime. I was very close but approximately wrong.

Dish and Clips- In Dish and Clips, the paper clip floated on top of the water. I thought, in my hypothesis that the clip would sink because it was denser than the water but the clip should be thought of as hollow and therefore not very dense instead of a solid metal. (I understand that the clip is a solid metal). My hypothesis was entirely refuted. 

Monday, September 20, 2010

Lab Report

9-13-1 Olivia Jacobs


Ellie Hogg

William Spencer

Topher Robinson

Watered Down Puns

Introduction

Water is the universal solvent and a basic necessity for all living things. Water also has many properties that affect the way it behaves under certain circumstances. Some of these are adhesion, cohesion, surface tension, capillary action, and polarity or hydrogen bonds. Adhesion can be described as the attraction among molecules of the same substance, while cohesion is the attraction of molecules of the same substance. Surface tension can be described as the affects of cohesion; otherwise the bonding of the water molecules on a surface. Capillary Action is the ability of water molecules to travel against gravity by adhesion. Polarity is the difference of charges in an H-Bond, creating a neutral molecule.

Monday, August 16, 2010

Sylabus and Labs

I am very excited for Biology this year. We have already taken quizzes on the syllabus and on a safety guide sheet. Mrs.Isaacs is awesome and I am reay for the year. Alot of my classmates are intimidated by her but I think she's just pushing us to do our best. :)

Thursday, March 4, 2010