Bellarmine Ecology

Ecology of the Bellarmine Campus 

The organisms: 

Producer: Grass (Agrostis):



    Grass not only covers the majority of the quad at Bellarmine, but "about one quarter of the Earth's land is covered with grasslands" -National Geographic. There are around ten thousand different species of grass, but the grass seen in the lawns at Bellarmine is known as Agrostis. According to the Lawn Institute, a 50 by 50 feet lawn of Agrostis releases enough oxygen to fuel a family of four! Not only is this fascinating organism able to sustain a family of four with oxygen, it is also in the beginning of the food chain, fueling almost every other organism on this blog. Grass is extremely versatile, allowing it to be located in many different diverse climates, the most prominent being grasslands, as we stated before.

Primary Consumer: Slug (Arion distinctus)



   Slugs are mollusks that are considered primary consumers because they absorb the nutrients directly from the plant producers that they eat. Slugs live in moist, cool environments, which explains why we found it under one of those concrete covers amongst the pipes, where it is very damp.

Secondary Consumer: House Sparrow (Passer domesticus)



   House Sparrows are carnivorous birds that eat small insects, making them secondary consumers. This bird was very shy and flew away from me, which explains why my picture is so poorly taken and from a distance. House sparrows are found in nature in grasslands, deserts and woodlands, but their local habitat is, as their name suggests, near human development, such as in the Bellarmine campus trees.

Tertiary Consumer: Cat (Felis catus)



   House cats are carnivores that each small animals such as mice, squirrels, birds, etc., making them tertiary consumers. Small house cats like this one are highly domesticated and are a product of selective breeding. Their local habitat is anywhere where there are humans, because humans keep them as pets. However, cats can escape and thrive in the wild, away from humans. In this case, the cat is roaming the streets near Bellarmine.

Decomposer: Mold (Stachybotrys)



   Black Mold is a decomposer because it grows on dead food, such as the lemon in this picture, and then breaks it down into its fundamental nutrients that can then be recycled into the food chain. Mold's local habitat is on numerous different foods such as bread, fruits, or pretty much any place that provides a source of food and moisture.

Herbivore: Garden Snail (Cornu aspersum)

 

   Snails are herbivorous mollusks, meaning they eat plants, which explains why we see this one chowing down on a leaf. The reason why there was an abundance of snails when I was taking pictures is because it was raining lightly. Some snails come out from their hiding places to prevent from drowning, others know that snails will be coming out of their hiding spots when it rains, so they too come to search for a mate. Finally, some simply come out because it is usually dark when it rains, and snails are nocturnal and need moisture. These snails are found nearly everywhere where there is vegetation for them to eat. This sometimes becomes a problem for people such as farmers whose crops get ravaged by snails.

Carnivore: Black Widow Spider (Latrodectus)

 


   Black widow spiders are carnivorirous archnids that feast on the poor insects that manage to get entangled in the spider's web. Not only do they eat small insects, the female black widows are also known to eat their mate. Black widows are considered to be one of the most venomous spiders in North America and most dangerous to humans. Unlike the brown recluse, they deliberately jump onto and bite humans. They live in temperate climates in dry, dark places. This is why they are often found in sheds or garages. I found the spider in the first picture under a stepping stone, and the second under one of those concrete covers.

Omnivore: Humans (Homo Sapiens)



   Humans are omnivores, meaning we can eat both plants and animals. One feature that helps us achieve this is our teeth; we have pointy canines for tearing meat, sharp incisors for cutting, and dull molars for grinding. Humans live pretty much everywhere worldwide, but the ones captured in this rare photo live somewhere in the San Jose area.

Threatened Species: Golden Bamboo (Phyllostachys aurea)

This species of bamboo, as well as most other species of bamboo is nearing endangerment, unfortunately. The reason for this is none other than Homo Sapiens. We have been deforesting bamboo forests because of how versatile bamboo is for building. You can even see in this picture that this mini-forest of bamboo has been slightly ravaged by humans. Destroying these bamboo forests is also harmful to the inhabitants, which explains why pandas are classified as endangered. Golden bamboo is not native to this area; it is mostly found in Asia, Australia, and South America. This specific bamboo patch is located between Sobrato and Liccardo.

Endangered Species: Ginkgo Tree (Ginkgo biloba):

 


   Ginkgo trees used to be extremely prevalent, but have dropped dramatically, leaving only two populations of Ginkgo trees: in the ian Mu Shan Reserve and the Zhejiang province in eastern China. Many thought that this tree was extinct. The reason for this tree's endangerment surprisingly has nothing to do with humans. These trees are gymnosperms, which are the earliest seed plants. Ginkgos are extremely old, older than dinosaurs. They are only tree ancient tree species that survived the extinction event, which is why they are often called "the living fossil." These trees live in temperate places with moist soil, such as the temperate climate and rich soil of the Bellarmine Campus.

Non-Native Species: Palm Tree (Arecaceae) 



   Palm trees are non-native to this area. There are some species of palm tree that are native to southern California Oasis's, but there aren't many of those. These trees prefer a tropical climate and often live near water. They are extremely versatile trees and can withstand harsher environments than other trees. When they live in places such as deserts that lack an abundance of water, they often aren't as tall so there is less water and energy loss during the transport of it to the leaves.

Pollution source: Leaf Blower



   Leaf blowers such as the one in this picture, as well as millions of other leaf blowers worldwide contribute greatly to pollution and increasing our carbon footprint. It burns fossil fuels in the form of gasoline, and releases nasty pollution into our atmosphere. The habitat of these beasts are in places full of leaves and other debris that need to be blown away.

Discussion Questions:

1. Define and differentiate between ecology and environmental science and discuss the Bellarmine campus in the context of both: Ecology is the study of how different organisms interact with each other and their environment, and how they are effected by abiotic and biotic factors, while environmental science is a much broader term that incorporates the information of numerous different sciences such as Ecology, Biology, Physics, Chemistry, soil science, and so on. They are both analyzing the environment and organisms in it, however, environmental science is a more in-depth analysis. We can use Ecology to analyze the Bellarmine campus by observing how a spider interacts with a tree by building a web on it, and with a fly by capturing and eating it. We can study the Bellarmine campus using environmental science by measuring the impacts humans pollution has on the organisms chemically or physically. 
2. Define and describe any population, community, ecosystem, biome and aquatic zone that you find on campus; and discuss the biotic and abiotic factors that contribute to that ecosystem: A population defines as a group of a species of animals living together. I found numerous populations. For one, I discovered a population of slugs, all living together under a rock. I also found a huge population of bees in a tree, all working together and thriving. Communities differ from populations because they are not limited to the same species; they can consist of many different types of species living together. Every organism on the Bellarmine campus could be considered part of a community because they are all living together in the same area. An ecosystem is the communities as well as the nonliving materials all living in conjunction. For example, the trees at Bell are nourished by the water and soil, or the gardener interacting with the non-living lawnmower, which interacts with the grass. The largest biotic factor of this ecosystem is humans. We pretty much have control over the ecosystem, whether we choose to help it thrive or destroy it. Some other biotic factors include predators such as cats eating populations of squirrels. Abiotic factors include the rain that nourishes the plants, the wind that spreads the seeds of plants, the sun's heat and light intensity, and so on. Biomes are classified by their temperature and vegetation. Because Bellarmine's climate is temperate, and there are trees and shrubs on campus. Therefore, the biome Bellarmine is located in is the Mediterranean forest or shrub biome. You could also break up Bellarmine's campus into mini-biomes. The football field could be grasslands, the place behind the chapel could be wetlands, the pool would be an aquatic zone, and the rest would be a mix between taiga and grasslands.
3. Construct and discuss a food chain, a food web, and an ecological pyramid based on the trophic levels that you observe. 

   As you can see in this food chain I constructed, the flow of energy begins from the sun and is captured by the leaves of the plants. Then, when the primary consumers eat the plant, they absorb a certain amount of the energy. When the secondary consumer eats the primary consumer, he absorbs a small amount from that organism, and so on. By the time the decomposer gets to the food, depending on which trophic level the organism was from, there will be very little energy left. Each time, 10% of the energy is available to the next trophic.



This ecological pyramid is a different way to view the food chain.



This food web makes it clear how the sun is the reason for all life, and how everything can be decomposed. It also shows that not all trophic eat only the immediate lower trophic, they can eat organisms from multiple trophics.

     4.  Investigate and discuss any endangered, threatened, and invasive species on campus: 
    On our campus, we have many different species of trees, flowers, and organisms that are either endangered, threatened, or invasive. I think that it is good we have these on our campus, as long as we take care of them. By taking care of them, we help slow down the process of extinction by increasing the number of living organisms in the species. After discovering the threatened and endangered species on campus, I discovered the causes of their loss in numbers. It was really sad to see that a large amount of them were endangered because of deforestation. For example, the bees are endangered because we are killing all the flowers and killing them with pesticides. This is again why it is good that we have a sort of safe haven for them to live in here at Bellarmine.

      5.  Define pollution, and describe and discuss the various types that you observe on campus.
   Pollution is when humans introduce a substance into the environment that is harmful or poisonous. While looking for sources of pollution, I was pleasantly surprised to see that the majority of carts being driven around were electric. This showed me that Bellarmine is somewhat trying to fight the pollution. We are far from pollution free, however. The dozens of cars that litter the parking lot all were gas guzzling. Also, the leaf blowers and lawnmowers used by the gardeners were gas-powered and releasing pollution. In the future, I would hope to see more solar panels and other forms of non-polluting energy implemented into the Bellarmine campus so we can help aid in the effort to save not just endangered species but all species from extinction.

Works Cited:

http://environment.nationalgeographic.com/environment/habitats/grassland-profile/
http://www.countrysideinfo.co.uk/grass_facts/
http://www.thelawninstitute.org/pages/education/lawn-facts-and-stats/lawn-and-turfgrass-facts-and-stats/
http://www.enchantedlearning.com/subjects/invertebrates/mollusk/gastropod/Slugprintout.shtml
http://www.softschools.com/facts/animals/sparrow_facts/322/
http://feline-nutrition.org/answers/answers-raw-diets-and-cats-what-about-eating-bones
http://web.utk.edu/~mtaylo29/pages/mold%20on%20wood.html
http://www.snail-world.com/garden-snail/
http://www.livescience.com/39919-black-widow-spiders.html
http://nationalzoo.si.edu/animals/giantpandas/pandafacts/
http://www.softschools.com/facts/plants/bamboo_facts/563/
http://ginkgobilobatheendangeredplant.blogspot.com/
http://www.kew.org/science-conservation/plants-fungi/ginkgo-biloba
http://bioweb.uwlax.edu/bio203/2011/lehrer_brit/habitat.htm

DNA IS NOT GARBAGE

DNA IS NOT GARBAGE

          Having the audacity to refer to DNA as garbage is a blatant sign of disrespect. As of now, we do not have the knowledge to know whether the "junk" DNA has a purpose. We are assuming that the only purpose of DNA is coding for protein, but there could be countless undiscovered phenomena that the "junk" DNA is being used for. It not just me who believes this, computational biologist Ewan Birney says, "What was once known as junk DNA turns out to hold hidden treasures." They have already discovered that some of the "junk" DNA is used for regulatory purposes, and this is just the tip of the iceberg. Other parts of it seem to have their own functions such as sensing chemicals in the cells. Who is to say that the remaining parts won't also have functions that are yet to be discovered. Scientists are hard at work on the ENCODE project, which is dedicated to find the purpose for the entire human genome. Until we have expanded our knowledge of DNA, it would be in our best interest to not call it garbage. 

Corn Genetics Lab

For this lab experiment, we put our knowledge of chi squares to the test. We did this by using indian corn. As seen in the picture, the corn had two specific traits, kernel coloration (purple or yellow), and kernel texture (smooth or shrunken).

We took a sample of five rows, and counted the different types of kernels. We choose five rows because, though it may be slightly less accurate, it was easier to do with the amount of time given. Our data is listed below.

Judging by our data, we concluded that the purple and smooth must be the dominant characteristics. We also assumed that the parents must have booth been heterozygous SsPp (S being texture, P being color). We assumed this because the expected ratio for two SsPp would be 75% to 25%, and our data was almost exactly that.

Now, we counted the number of each specific combination of traits in the five rows of the corn. Our results are listed below.

Luckily, we obtained the expected 9:3:3:1 ratio, which means that the genes are located on the same chromosome and do assort independently. This 9:3:3:1 ratio is the expected ratio between the two heterozygous parents. We created a punnett square of the parents to ensure that the expected ratio is correct. 

Dark Purple = Purple and Smooth (9)
Light Blue = Purple and Shrunken (3)
Orange = Yellow and Smooth        (3)
Yellow = Yellow and Shrunken     (1)

Now, time for the Chi Square part. We calculated the individual chi square values for each row and added them all together to determine the overall chi square value. We once again used a table:

Then, we determined whether the chi square value is a good fit with our data. We were told that the degrees of freedom (df) is the number of possible phenotypes - 1. We then circled the row on a chart that was closest to our chi square value. 

The closest value is between .58 and 1.42 under the "Good Fit Between Ear & Data" section. "Good fit" and "poor fit" are referring to how your observed ratio is to the expected ratio of 9:3:3:1 that would result from the PsSs parents. Our data was surprisingly close to the expected value, however two reasons the data would have a poor chi square value are if you get unlucky and choose a dud set of rows that don't exhibit the correct ratio, or you simply counted wrong. 

Chi Square Problem Set:

1. Problem: A large ear of corn has a total of 433 grains, including 271 Purple & starchy, 73 Purple & sweet, 63 Yellow & starchy, and 26 Yellow & sweet. 

Your Tentative Hypothesis: This ear of corn was produced by a dihybrid cross (PpSs x PpSs) involving two pairs of heterozygous genes resulting in a theoretical (expected) ratio of 9:3:3:1

Objective: Test your hypothesis using chi square and probability values. 

The chi square value was in the poor fit section, meaning that the that the genes are not located on the same chromosome or do not assort independently. Therefore, my hypothesis is wrong. 

2. Problem: In a certain reptile, eyes can be either black or yellow. Two black eyed lizards are crossed, and the result is 72 black eyed lizards, and 28 yellow-eyed lizards. 

Your Tentative Hypothesis: The black eyed parents were Bb x Bb

Objective: Test your hypothesis using chi square analysis. In this set, because only two values (traits) are examined, the degrees of freedom (df) is 1. SHOW ALL WORK!

Expected:75% Black
25% Yellow

My hypothesis is correct because the chi square value lands in the "good fit" section, meaning the parents are both heterozygous black (Bb). 

3. Problem: A sample of mice (all from the same parents) shows

58 Black hair, black eyes 16 Black hair, red eyes 

19 White hair, black eyes 7 White hair, red eyes

Your tentative hypothesis: (what are the parents?)

Objective: Use a chi square analysis to support your hypothesis

Total = 100

Black hair = dominant (H)

Black eyes = dominant (E)

Hypothesis: parents are heterozygous black hair, black eyes. HhEe and HhEe

Expected ratio would be 9:3:3:1

The chi square value lands in the "Good Fit," meaning that my hypothesis is true and the parents are heterozygous black hair, black eyes (HhEe).

Conclusion

This lab activity made my understanding of chi square much more clear. It seems tough at first, but as long as you remain organized and show all your data in a neat chart, it's surprisingly easy. Aside from chi square, this lab has taught me to be an adept user of excel and to have the patience to count hundreds of corn kernels. I hope Mr Wong has uses similar labs to explain hard concepts because I believe that hands-on work is how I learn best.

Meiosis

For this project, I had the privilege to study the process of Meiosis by creating a stop motion video. In order to do so, I had to dig deeper to find out what Meiosis actually is. I learned that Meiosis can also be referred to as reductional division. Meiosis is the foundation of sexual reproduction. Through two stages and multiple phases, Meiosis creates four haploid cells from one diploid cell. Each haploid cell has half the amount of genetic material as the original cell, meaning that it does not have enough chromosomes to create a new organism alone. This is why two haploid cells, one from each parent, must join together in a process called fertilization to form a diploid cell with enough genetic information to create a new organism. Meiosis is similar to Mitosis, but it only occurs in germ cells. The most common type of germ cells are gametes: sperm for males and eggs for females. Meiosis serves to create genetic variation within a species. It does so with two main events: crossing over and independent assortment. Crossing over occurs during prophase 1. When the chromosomes come close enough together, there is a chance that a chromatid from one chromosome crosses over onto the other chromosome (seen below). Now, each chromosome contains part of the other, thereby increasing genetic variation.

The other way genetic variation is achieved through Meiosis is through a process called independent assortment. This occurs when the haploid cells from the male and female combine to form a diploid cell. Each parent's slightly different traits have a random chance of being in their offspring. For example, in the picture below, the offspring has a chance of having traits from the dad, mom, or a mix of traits from both. 

This genetic variation is key to the survival of a species. This is because it allows individual organisms to have certain traits that allow them to survive better, which forms the basis of natural selection and evolution. However, if just one small error occurs during Meiosis, the offspring may have significant deformities. One way Meiosis could go wrong is non-disjunction. Non-disjunction is when homologous chromosomes fail to separate into their daughter cells (seen in the picture below).

This may result in diseases such as Down syndrome, Triple-X syndrome, Klinefelter's Syndrome, and Turner's Syndrome. This is also the reason that panda bears have 42 chromosomes, while normal bears have 74. Pandas may have come into existence after a disjunction occurred during meiosis of a normal bear. The result was a odd colored bear with less chromosomes. However, this color turned out to be an advantage for Pandas because the flashy color helped them to find others to mate with and ward off dangers in their bamboo habitat. This proves that non-disjunction doesn't always result in physical ailments, but can instead aid in the process of natural selection. Sadly, now that bamboo forests are disappearing, pandas are becoming endangered because their colors are no longer an advantage to them.

The final version of our stop motion movie is below. Having had some previous knowledge of stop motion movies, this project was the most fun so far. I'm very happy with how it turned out. However, in order to improve this lesson, I would recommend giving us more time to work on our project. Doing so would allow us to make a more smooth video with more frames. It would also allow us to plan through exactly what we wanted to do, so we could avoid making silly mistakes and having to restart like my partner and I did. Other than that, this was an amazing experience and I hope Mr. Wong lets us do more projects like it!

https://www.youtube.com/watch?v=AHoBRteLK1s

Works Cited:

http://www.biology.iupui.edu/biocourses/N100/2k2humancsomaldisorders.html

E.O. wilson textbook

http://www.reddit.com/r/askscience/comments/2ommzw/how_often_are_there_genetically_identical/

Cancer Interview

      I had the privilege to interview a former breast cancer patient. She is currently 50 years old, and her cancer was diagnosed when she was 44. She first noticed that she had cancer when she noticed a pea-sized lump during a self-examination. She later confirmed it was cancer with a mammogram, ultrasound, and biopsy. She also had an MRI to ensure that the cancer had not spread. Other than the lump, she had no symptoms. Her initial reaction was terror, followed by extensive amounts of research. Her treatments included lumpectomy, bilateral mastectomy, lymph node biopsy, 6 weeks of radiation, and hormonal treatment with tamoxifen. The radiation killed leftover cells on her chest, and the tamoxifen is a systemic treatment that binds with estrogen receptors on the cancer cells which then prevents cancer cells from growing. Side effects from her tamoxifen were leg cramps and hot flashes which caused sleep disruption. She also had slight memory problems caused by the tamoxifen. Through her entire cancer ordeal, she learned to appreciate time with family and friends more, and she grew closer to those who supported her. Some misconceptions about cancer are that cancer is always curable and the idea that people must have done something wrong to get cancer. Another big misconception is that mammograms can detect all breast cancer. Her piece of advice is to check your family history and if cancer runs in the family, you need to be getting periodic MRI scans because mammograms sometimes can’t detect cancer in younger women. Also it is crucial to get exercise, eat vegetables, drink alcohol moderately if at all and avoid smoking. 

Then, I did some research. I learned that there are two main types of breast cancer:

1. Ductal carcinoma in situ (DCIS). This is the most common type of non-invasive breast cancer. The word "ductal" refers to the location that the cancer starts, the milk ducts (as seen in the picture below). "Carcinoma" refers to all types on cancer that occurs in the tissue that lines organs. "In situ" means "in its original place." This type of cancer is label "non-invasive" because it is only in the milk ducts, and hasn't begin to spread to the rest of the breast. DCIS by itself isn't life-threatening, but it has a risk of developing into an intrusive cancer, which is very life threatening. Also, DCIS patients are at higher risk of the cancer returning, which is why my interviewee opted for a mastectomy.
2. Invasive (or infiltrating) ductal carcinoma. This type of breast cancer is the overall most common and is the type that afflicted my interviewee. Again, this cancer starts in the milk ducts, but unlike non-invasive, the cancerous cells tear through the ducts and grow into the fatty tissue in the breast. From there, it can spread to other parts of the body and be possibly fatal. This is why my interviewee must take tamoxifen for 10 years after her surgery: to prevent the cancer from metastasizing in other organ tissues such as bones or liver. Some patients with more aggressive forms of cancer must also undergo chemotherapy treatments. Chemotherapy is effectually a poison that targets fast growing cells such as cancerous ones. Unfortunately, chemotherapy can have terrible side-effects that can danger the life of the patient. Fortunately, my interviewee had a cancer that was determined through an Oncotype DX test of the tumor to not require chemotherapy.

Some breast cancer is hereditary, which means it is inherited. There are genetic tests that can detect only a limited number of those hereditary types, specifically those associated with the brca I and brca 2 genes. Other than having it in your genes, there are no clear causes of breast cancer, it is mostly bad luck. It could be generated by random mutations during cell division.  The reason people get breast cancer is because of the cell cycle. All cells in the body are regulated by the cell cycle, so if something goes wrong during the cell cycle, it can cause immense damage. The breast tissue of women are extremely sensitive to cancer causing agents. During the cell cycle, a cancer causing agent inflicts damage upon the DNA, or "mutates" it. The result can be a DNA strand with missing base pairs. These missing bases can lead to cancer. Another mutation that occurs is when the cancer causing agent takes over a base, causing an incorrect pairing. As my interviewee stated, the best prevention of breast cancer is to get exercise, have a heathy diet, and avoid smoking and alcohol.

Some other interesting and alarming facts regarding epidemiology I learned about breast cancer include:

• Breast cancer is the most commonly diagnosed in women, but men are still susceptible, with 2,150 men diagnosed and 410 dead because of it each year
• Breast cancer is the 2nd biggest cause of death in women, heart disease being 1st
• Of the 220,000 women diagnosed with breast cancer each year, 40,000 will die of it

But HAVE FAITH! Deaths due to breast cancer have been slowly decreasing since 1990 due to better detections and treatments, and is expected to decrease more as technology improves.

This experience was very eye-opening to me, because I never realized how much cancer effects someone's life. I am also very thankful that my interviewee was able to discover her cancer before it was serious. Cancer, now more than ever,  acts as an enormous dissuasion for me to stay away from not only smoking, but also alcohol.


Sources:

http://www.nationalbreastcancer.org/
http://www.cancer.org/cancer/breastcancer/detailedguide/breast-cancer-breast-cancer-types
http://www.breastcancer.org/

Mitosis Blog Report

For this lab activity, we used microscopes to examine the different stages of cells. We examined two materials: whitefish blastula and onion root tips. First we located the whitefish blastula under the microscope using a 10x lens. Once we found it, we used a 40x magnification lens to zoom in closer to the individual cells.

The whitefish was full of cells in different stages of the mitosis, majority being interphase. The cell circled in green is in metaphase because the chromosomes are lined up in the center of the cell. The one circled in red is in early anaphase because the chromatids have started to move to opposite sides of the cell. The one in blue is telophase because the cell has started to pinch itself in half. I never knew how easily you could see the individual spindle fibers without a high power microscope.

Next, we moved on to onion root tips. We followed the same steps of finding it with 10x and zooming in with 40x.

Again, almost all the cells were in interphase, except a few along the side of that arrow that were in late anaphase.

For the next part of our experiment, we estimated the relative length of time that a cell spends in the different stages of cell replication. For this part, we only studied the onion root tip. We were told that the length of the cell cycle is approximately 24 hours for onion root tips. First, we counted the number of cells in each stage in two fields of view. Using that information, we calculated the percent of the total cells are in each stage, and then multiplied that number by 24 hours (1,440 mins). By doing so, we estimated the amount of time the cells spend in each phase. Our data is recored below:

Analysis: 

1. It is more accurate to call mitosis "nuclear replication," rather than "cellular divison," because the nucleus isn't dividing, it is replicating.
2. Whitefish blastula and onion root tip are selected for a study of mitosis because these cell tissue types are known to have rapid cell division rates. Also light can pass through them easily, allowing them to be viewed with a light microscope. 
3. If my observations had not been restricted to the area of the root tip that is actively dividing, my results would have had only cells in interphase, which makes me wonder if the root tip we observed are beginning to stop dividing and thus have mostly cells in interphase. 
4. Based on my data, I can infer that, starting with interphase, each stage is dramatically shorter than the previous one, except for anaphase and telophase.

Catalase Lab

Objective:

In this lab activity, we studied the factors that effect the activity of enzymes. Catalase is a type of enzyme that is found in most cells that speeds up the break down of hydrogen peroxide. Ridding the body of hydrogen peroxide is crucial because hydrogen peroxide is very lethal and kills nearby cells.

Materials:

• 50 mL beaker
• 10 mL and 50 mL graduated cylinder
• Catalase solution
• Filter paper punches
• Hole stopper
• Stop Watch (iPad)
• Reaction chamber
• Tweezers
• Tub of water

To begin, we took the vial of catalase solution and carefully dipped a filter paper punch in it using tweezers. We then stuck the soaked paper to the top, inside wall of the chamber. Next, we added 10 mL of 3% hydrogen peroxide into the chamber, making sure it didn't touch the filter paper. If it had touched the filter paper, it would start to react, and ruin the experiment.

                           
                           

We then put in the stopper and placed the entire contraption into the water. Next, we filled the cylinder with water by laying it horizontally and letting the air bubbles out and carefully tilted it into a vertical position, making sure the water stayed in it. Then for a whopping ten minutes, we held the graduated cylinder above the chamber to catch the released oxygen, making sure to switch places when our arms began to cramp. Now for the science behind it! Hydrogen Peroxide naturally decomposes when exposed to light in this reaction: 2 H202 -> 2 H20 + 02. The rate of this decomposition changes due to factors such as temperature,  concentration, and pH. Sadly, we only were able to experiment with concentration. Hydrogen Peroxide begins to decompose when exposed to sunlight because the light provides enough energy to exceed the required activation energy and begin the reaction. This is why Hydrogen Peroxide is kept in dark, opaque containers to prevent the decomposition from commencing. Catalase speeds up the decomposition by finding a way to orientate the hydrogen peroxide molecule in a way that the oxygen can be freed more easily. Back to our experiment. Using the scale on the side of the graduated cylinder, we measured the amount of oxygen produced every 30 seconds. The results were nearly linear! We repeated the same steps with 2 and 4 paper punches. Our results are below:

Sadly, we were short on time, so we weren't able to do 3 paper punches and could only do 5 minutes of the 4 paper punches. Looking back at our data, we concluded that each paper punch of catalase sped the reaction time up by about 3 times. This was a little surprising because one would assume having two instead of one would only be twice as fast if the rate is related to the surface area of the paper punch or the total volume of the Catalase.  Therefore, there must be another factor that we don't yet understand.