Photosynthesis Virtual Labs Analysis

Photosynthesis Virtual Labs

Lab 1: Glencoe Photosynthesis Lab

Analysis Questions

1. Make a hypothesis about which color in the visible spectrum causes the most plant growth and which color in the visible spectrum causes the least plant growth?

If red, blue and violet are best used by plants, then plants will grow best under these colors.

If green and yellow provide the least energy for plants, then plants will grow worse under these conditions.

 

2. How did you test your hypothesis? Which variables did you control in your experiment and which variable did you change in order to compare your growth results?

I used the light and plant growth virtual lab and measured the average heights of the plants under the different conditions. In this lab, there was no control lab to compare to, and the independent variable was the color of the light used.

Results:

Filter Color	Spinach Avg. Height (cm)	Radish Avg. Height (cm)	Lettuce Avg. Height (cm)
Red	18
Orange	14
Green	2
Blue	19
Violet	16

3. Analyze the results of your experiment. Did your data support your hypothesis? Explain. If you conducted tests with more than one type of seed, explain any differences or similarities you found among types of seeds.

The data supported our hypothesis as the colors which we predicted would grow plants better had higher average heights and the colors which we predicted would do worse had lower height averages.

4. What conclusions can you draw about which color in the visible spectrum causes the most plant growth?

Colors closer to the end of the visible color spectrum provide more energy and help plants grow better than visible light closer to the middle of the spectrum.

5. Given that white light contains all colors of the spectrum, what growth results would you expect under white light?

I would expect plants under white light to grow the best and have the highest average height because white light contains all the colors in the spectrum and thus has the combined energy of all of them.

Site 2: Photolab

• Question: Does the amount of carbon dioxide present during photosynthesis affect the rate of photosynthesis?
• Hypothesis: If photosynthesis uses carbon dioxide to create glucose, and to gain more of a product you need more of the reactants, then an increase in carbon dioxide levels will increase the rate of photosynthesis.
• Experimental Parameters:
• Dependant Variable: The amount of oxygen released.

• Independent Variable: Level of carbon dioxide in the water.
• Control: Water with a low level of carbon dioxide.
• Constant:
• Temperature: 10
• Light Intensity: 20%
• Data Table

Amount of Oxygen Released
Time:		15s	30s
Levels of Carbon Dioxide	High	4	8
	Low	3	6

Conclusion

In this lab we asked the question, does the amount of carbon dioxide present during photosynthesis affect the rate of photosynthesis? We found that the amount of carbon affects the rate of photosynthesis. For every 15s in the virtual lab, when there was a low amount of carbon dioxide, only 3 bubbles rose, while the high amount of carbon dioxide caused 4 bubbles. The bubbles are a product of photosynthesis as the oxygen is released and causes a bubble to rise to the top. Also, to create a faster rate of reactions and more products in science, you need a higher amount of reactants, which is why a higher amount of carbon dioxide causes a faster reaction and more product. This data supports our claim because it shows how a higher amount of carbon dioxide increases the reaction and shows the differences caused by varying amounts.

This lab was done to demonstrate the effects of external parameters on the rate of photosynthesis. From this lab I learned how different external environmental changes affect the rate of photosynthesis, which helps me understand the concept of photosynthesis and how an increase in reactants increases the rate and product from a reaction. Based on my experience from this lab, I now know how to design a functional experiment and how to change variables to answer questions.

Unit 3 Reflection

       Unit 3 of biology was about the characteristics/structure of cells and how they function and create energy. The themes of this unit were how cells create energy, the different kinds of cells, the functions of cell organelles, and diffusion. Learning about osmosis and diffusion was easy because they are based of the principles of high and low concentration and how molecules move from low to high concentration. The vodcast on osmosis and diffusion helped to explain this, as it clearly showed how water diffuses to compensate for the size of other molecules. the egg diffusion lab clearly showed how osmosis works in real life conditions and gave a hands on experience into cellular biology. The vodcast on the different parts of the cell was interesting because it was done by someone else, and it gave a broader understanding of the functions of the different organelles. The microscope lab experiment helped to identify the different parts in cell and was very fun, though finding many of the organelles proved challenging. On the other hand, learning about photosynthesis and cellular respiration was harder than expected. Even though the vodcasts on these topics were very in depth, the complexity of the topics was much harder to remember. The text book notes gave an even deeper insight on the process that occurs in both, but the lack of background knowledge I had on both hurt me, as I didn't truly understand the reactions occurring in the cell. I still don't understand how exactly the cell converts light into energy, and weather the ATP is molecule or from of energy. This unit helped become a better student by forcing me to study and learn more about concepts I didn't understand. I previous years, I picked up and remembered lessons very quickly, so this unit was a change because I had to actually study on the topics of cellular respiration and photosynthesis. Some questions I have include: Is ATP and actual molecule or an invisible energy?; why do certain light waves have less energy than others?; If cells can still create energy without oxygen, how long can the body survive without oxygen?

Egg Diffusion Lab Analysis

          In this lab, we observed the quantitative change to the mass and circumferences that occurred when eggs were placed in different solutions. The eggs were first placed in vinegar to dissolve the shell and then were placed in deionized water. Next, were collected data on the mass, circumference, and qualitative features of the two eggs. One of the eggs was placed in deionized water again, while the other was placed in corn syrup. The egg in the water grew in size, while the egg in syrup shrink in size and became translucent.

          On average, the mass and circumference of the egg in the increased sugar concentration decrease by -51.7% and -23.67% respectively. The cause of the change was the high concentration of sugar outside the cell caused the water to diffuse to the sugar, causing the egg to shrink. Molecules move from areas of high concentration to areas of low concentration in order to create equilibrium, but sugar molecules are to large to diffuse through the semi-permeable membrane, so the smaller water molecules will move to the sugar through passive diffusion to compensate for the sugars immobility. The effect of this is seen in our data.

          A cells internal environmental condition changes based on its external environment because needs to properly compensate with the changes in order to survive. This can happen from the movement of water from areas of low solute concentration to areas of high solute concentration.  

          This lab demonstrates the principal of diffusion by showing a real life example of how diffusion occurs and the effects of it on cells.

          Fresh vegetables are sprinkled water because the water diffuses into the cells sue to a low solute concentration outside the cell, thus keeping the vegetables from becoming limp. The salt accumulated alongside roads can cause the vegetable cells to become hyper tonic because there is larger concentration of solute outside the cell, causing water to diffuse from the cell towards the cell.

          Based on this experiment I would want to test the effects of salt water on the human body and what it does to it. This relates to the previous experiment as it to deals with diffusion, but this experiment would go more in depth into the biological effects of shrinking cells on the human body.  

Egg Cell Macromolecules Lab Analysis

In this lab we asked the question "can macromolecules be identified in an egg cell?" We found that each part of the egg cell contained different macromolecules through a series of tests. To test for the different macromolecules, each part of the egg was placed in a solution that contained solvents that reacted with the macromolecules.

The egg membrane tested positive for lipids, polysaccharides, and monosaccharides. The polysaccharide turned black from the iodine test, and the lipids turned orange from the Sudan III solution, while the monosaccharides turned blue from the Benedicts solution test. These tests show that the egg membranes tested positive for these different macromolecules as the colors observed changed from the presence of the macromolecules. This is because the cell membrane is made of phospholipids and carbohydrates are found on the outside of membranes for communication.

The egg white tested positive for all of the macromolecules we tested for. he polysaccharide turned black from the iodine test, the lipids turned orange from the Sudan III solution, and the proteins turned purple from the sodium hydroxide copper sulfate solution, while the monosaccharides turned blue from the Benedicts solution test. These tests show that the egg membranes tested positive for these different macromolecules as the colors observed changed from the presence of the macromolecules. This is because the egg white is used as energy storage for the nucleus, so  carbohydrates and lipids a re stored there. It also contains proteins for proper growth, development, and protection (enzymes for immunity).

The egg yolk tested positive for polysaccharides and monosaccharides. The polysaccharide turned black from the iodine test, and the monosaccharides turned blue from the Benedicts solution test. These tests show that the egg membranes tested positive for these different macromolecules as the colors observed changed from the presence of the macromolecules. This is because the egg cell nucleus is made of carbohydrates for energy and structure and contains an inner membrane that uses them for communication. In addition, the egg yolk should have tested positive for proteins and lipids as proteins make up the nucleus of the cell and the lipids are used to store energy for development.

        While our hypotheses were supported by our data, there could have been possible errors due to human error and difference data collection. The human error came in many forms, such as problems in measuring liquids for the different macromolecule tests and accidental mixing of the solution. These errors may have impacted the data, as improper liquid measurements lead to inexact solution levels, so the egg cell parts may have been exposed to an improper levels of solution, which would change the qualitative color change. Accidental mixings of the solutions may have diluted the color into the egg cell parts, thus changing the color outcome. Another error was the difference in data collection and observation. Because the data was qualitative, it was subjective to opinion, and people interpreted the changes in color differently, so the data may have been slightly altered. Due to these errors, in future experiments I would recommend being more accurate when measuring items, which may be impossible to cease, and creating a more quantitative way of measuring the qualitative data.

         This lab was done to demonstrate what parts of cells the where macromolecules are found in cell. From this lab I learned what macromolecules are found in the different parts of cells and what they are used for, which helps me understand the concept of cells and their different organelles. Based on my experience from this lab, I now know what cells are made of, which will provide context and background information for other parts cellular anatomy.