Friday, December 20, 2013

Cell Communication Lab

Purpose 
Our purpose in this lab was to see how cells communicate among each other to reproduce and send signals without moving
Introduction
Cells communicate when and where to breed through quorum sensing. This is how yeast reproduces. In the lab we were seeing how each cell responds to this. 

Methods
We took cultured yeast and labeled at as a, alpha, and mixed, added broth and santatized water, we took it under the microscope and looked at the particles of yeast through the microscope after incriminats of 30 minutes, 24 hours and 48 hours and counted to see how much they increased. 
Data
In the lab, we noticed a pattern of yeast growth in the alpha-type in both single and budding haploid. But in the a-type, there is no pattern of growth. 


Graphs and Charts

Discussion
In this lab our data varied between the a type, alpha and the mixed. The most particles were present in the mixed, as expected. The third reading of ours type culture was screwed up because what was seen on the slide was spread out, moving the spread of cells in the third view. They weren't even throughout the slide or the test tube we were keeping them in. If we were to increase validity in our experiment we would have more than one sample of each culture to see variations in each. In our graph each "reading" (1, 2,3, and 4) they each represented different amount of time reading one was as soon as we put everything together in the tube, reading 2 was after a half an hour, 3 was after 24 hours, and 4 was 48 hours. We would extend the experiment over a longer amount of time and calculate the amount of percentage increase after each day to see how much they increase per day over a week of time
Conclusion
The cells will continue to divide over time. This leads to most haploid cells that then come together to form the budding. The yeast will continue to divide and grow indefinitely. 
References 
The lab
The book


Monday, November 18, 2013

Cell Respiration Lab

Purpose
The purpose was to compare the co2 emissions of germinating to dormant seeds. Also it was to determine the effect that temperature has on the cellular respiration. 

Introduction 
In this lab we measured the co2 that the germinating corn seeds produced. They are producing co2 because they are undergoing cellular respiration. A dormant seed has all the materials and food it needs to become a plant. When the seed becomes moist, the enzymes inside it start facilitating cellular respiration to make all the energy that the plant will need until it can go through photosynthesis.

Methods
In this lab we took the already germinated seeds and measured the amount of CO2 with the monitor to see what had the highest rate if respiration in ten minutes. Our group did corn, and we put it in ice cold water, to see what effect tempurature had on the rate of respiration. we used glass beads as a control group to make surety monitor was working properly.




Data
In our experiment the room was 24 degrees Celsius, and the cold water was 20 degrees celcius. The germinated seeds respirated at .66274 (ppm/s), and the germinated seeds in cold water respirated more at .68034 (ppm/s). The non germinated seeds respirated a ton less at .25721 (ppm/s). 








Graphs and Charts


Discussion
For the glass beads and the the non germinating seeds, both remained constant, neither showing any increase in CO2 output, which was to be expected. The germinating seeds at 24 degrees Celsius had a rate of .66 ppm/s while the cooler seeds at 20 degrees Celsius hade a rate of .68 ppm/s. This might not be accurate because the seeds at 20 degrees were not recorded for the full 10 mins. After 320 seconds, our group ran out of time. The rate of CO2 the seed produced could have slowed and ended with a slower rate after 10 minutes. If doing this experiment again, we would run each trial to the full time length. We would also soak the seeds in the ice water longer, further reducing their temperature. For the most part, the data did represent what we thought would be the results of the experiment. The glass beads are not alive, therefor not producing CO2. The no germinating seeds are not growing or using energy, so the would have no need to go through the process of cell respiration. Both germinating seeds would be going through cell respiration because they are growing. The cold seeds may have been producing more CO2 because they are trying to stay alive in the cold environment, and go through more cellular respiration to produce more heat. If I the data is inaccurate and the respiration rate should have been decreasing, it could be because the cold slowed the metabolic process down, affecting the CO2 output.

Conclusion 
The answers to the questions that we were finding were that the germinating seeds gave off more co2  than the dormant seeds, which means that they were respirating more. Also, the seeds germinated more at lower temperatures. 

References 
www.vrml.k12.la.us/rpautz/documents/.../respirationofgerminatingseeds.pd...

Tuesday, November 12, 2013

Enzyme Catalysis Lab

Enzymes and Catlysis Lab Report

Purpose
In this lab we were presenting how enzymes work and how they speed up reactions. 

Introduction
Enzymes are proteins that act as catalysts in a biochemical reaction. That means that they make a reaction go faster. They do this by lowering the activation energy, or the amount of energy needed to kick start a reaction. This allows reactions to take place at lower temperatures with more frequency. When an enzyme catalyze a a reaction it uses up the substrate to make a product. An enzyme can also be denatured, or broken, when taken out of its optimal pH or temperature, so one could stop a reaction by adding acid, because that would lower the pH. 

Methods - In the experiment, we took 10 ml of hydrogen peroxide and added 1 ml of catalase. We then swirled the solution and added sulfuric acid, denaturing the enzymes, stopping the reaction. Ww repeated this multiple times, but swirling for 30, 60, 90,120, 180 and then 360 seconds. We took a 5 ml sample of each and titrated the solution with potassium permanganate to fine out how much hydrogen peroxide was used up in each reaction. 

Data 
In the baseline there was 3.5 mL of hydrogen peroxide the whole time, in the final reading it started at 18.3, and after we put the enzyme in after 360 seconds the amount of hydrogen peroxide went down to 7.5 ml. The amount of hydrogen power oxide kept going down after we put in more KMnO4 because the enzymes caused the reaction to speed up and the ml drop after a shorter period of time.
Graphs and Charts 



Discussion
The overall trend of our results was that the longer we let the reaction go, the more substrate was used up. The only section that didn't follow this trend was at 30 seconds, but this may simply be because the measurement wasn't taken correctly. The initial and final reading go down every time because we titrate every time so more kmno4 was used. The amount of kmno4 used in the reaction goes down because that plus the amount of substrate has to add up to 3.5 (the baseline). The way to revise this experiment would be to make sure the titration Was done and read correctly. That is the point where it could've gotten messed up. The results of the experiment do support what we thought was going to happen because the longer the reaction goes, the more substrate gets used, just as we thought. 

Conclusion
There was no set question for answer for this lab, it was just an depth look at what we were studying in class. This experiment showed us the effects of a catalyst and it affects the rate of a reaction. We also better understood the idea of enzyme denaturing. In this case, there was a stop in the reaction because it was taken out of its optimal pH by adding sulfuric acid. 
References
The lab

Thursday, October 24, 2013

Diffusion and Osmosis Lab

Purpose
The purpose of lab 1A was to demonstrate what a selectively permeable looks like. The independent variable was the solution we put in the dialysis bags. The dependent variable was the color that the solution turned. This demonstrated selective permeability because we could actually see that only iodine could come through the bag. 
The purpose of 1B was to provide an example of osmosis. The independent variable was the solution that we put in the dialysis bag and the dependent variable was the weight when the experiment was done.  This shows osmosis because we could see how things went from a high concentration to a low, which caused the change in weight. 
The purpose of 1C was to show how water potential works. We could see how the potatoes swelled or shrunk. The independent variable was the solutions that we put the potato cores in and the dependent variable was the weight of the potato cores. 
The purpose of 1E was to show how the cells react to diffusion and osmosis. We could see how the cells swelled or shrunk. 

Introduction
A selectively permeable membeane allows certain molecules in and out of the cell. Molecules will diffuse from a higher concentrition to a lower concentration until the each equilibrium-the point that there is equal quantities on both sides-and there will no longer be any net movement of particles. Osmosis refers to the diffusion of water and dialysis refers to the diffusion of solid particles. Water potential is a property which predicts which way water will flow. It is determined by solute concentration and pressure. Water will move from areas of high water potential to low areas of water potential. 
 Methods
1a
      In this portion of the experiment we took a dialysis bag and filled it with sugar water in the cup. We took this bag and placed it in a iodine-water mixture. We waited for around 25 minutes and took out the dialysis bag to see the new concentration of the sugar water. The dialysis bag acted as a semi permeable membrane.
1b
    In this part of the experiment we took 6 dialysis bags and filled them with different concentrations of sucrose. We placed each bag in a cup of water and proceeded to wait for 30 minutes to see if the mass of the bags had changed. Again, the dialysis bag acted as a semi-permeable membrane. 
1c
     We used a cork borer to cut 24 potato cylinders (4 per cup). Then we weighed and recorded the 4 cores that went in each cup. Each cup had a different solution in it. After letting the potato cylinders sit for a while, we pulled them out and weighed and recorded them again. 
1e
     In this part of the experiment we looked up picture for onion cells to see when it would look like in Hyper, hypo and iso tonic environments. 

Data
1a Before the dialysis bag was dropped into the iodine solution, it tested negative for glucose. The bag was clear and the iodine solution was scarlet. After letting the bag sit, it turned a black/blue color and both the bag and iodine solution tested positive for glucose. 
1b For each bag, the mass increased after it was dropped in the water. The change in mass varied from 3.16% to 16.88%. 
1c For every bag, the mass increased after the were left to sit in the sucrose solutions. For the most part as the molarities of the sucrose went up, so did the weight that the bag gained.
Graphs and charts
1a
1b


1c
1e

Discussion
In these experiments we demonstrated how semi permeable objects work like the cell membrane. As well as presenting how a semiPermeable membrane works, we demonstrated osmosis, water potential, and how cells react to diffusion and osmosis. We saw in experiment 1a that the dialysis bag only let in glucose into the bag, instead of letting all parts of the iodine in. The strips changed to show that glucose was in fact present. In experiment 1b when we took the dialysis bags and filled them with solutions with different levels of sucrose, and we saw that the higher the molar it's of sucrose, the higher the mass went up. In 1c, where we took the potatoes, we saw that the potato cores gained in Mass while it sat In the sucrose solutions. In 1e, we looked at photos of onion cells in hypertonic, isotonic, and hypotonic solutions. This let us see how our cells react to the different environments around it.
Conclusion
Throughout all the experiments, there wasn't a question that we were to answer. They were more to demonstrate the concepts we learned in class. 1A showed how a membrane can be selectively permeable by only letting iodine through. 1B showed how water flows in osmosis. 1C showed what water potential is, using the potato as an example. 1E gave an example of how diffusion and osmosis affects the cells in our body.

Monday, September 30, 2013

Restoration Ecology Field Trip

Shannon:

On Wednesday at glacial park we spent most of the day clearing out invasive species in an area, and planting seeds and watering trees in a different area. Although the clearing out gave more of an initial feeling of gratitude and a better visual of what we were doing, planting and watering also gave a benefit to the area, even if we couldn't see it. Restoration ecology is something everyone should be involved in, to help the environment they are destroying. There isn't a downside to restoration ecology except for the manual labor you have to put into it. It is definitely worthwhile because in years to come the earth is going to be in a worse ecological state because humans have spent hundreds of years destroying what is naturally around them, and shouldn't we fix what we destroyed? I think so

    
  Before we started hacking away the invasive species
 
After we got a lot of chopping and removing done, you can see the difference and see more through the area where we were attempting to get it back to its original state.

Colin White:


I found going to Glacial Park fun and exciting. I learned a lot about the importance of restoration ecology and how much work goes into it. Once i started getting deeper into the brush, it was great helping each other and using teamwork to clear everything. Afterwards, seeing the changes we had made was instantly gratifying. One could see how much clearer the area looked. Doing this was my favorite part of the trip. However, I still did enjoy watering the small trees and planting acorns. It was a nice break from all the physical activity and I still felt the difference I was making. I liked the hands-on experience of the trip and the real world application of biology. I thought it was a worthwhile investment of our time to be there and that we had some effect on the ecosystem. 

Lab partner planting an acorn


Me and my classmates clearing honeysuckle and buckthorn 


Colin Schenkel:

When we first got to the section that we were going to clear out it looked like this.  It was all overgrown with plants that weren't native to that area. 

l
we cut this down
l
V




This is what the area looked like when we were done. It was all cleared out. I do think that the restoration ecology is worthwhile, because It helps the environment by letting all the natural species come back. It takes a lot of work, but I enjoyed the immediate satisfaction of seeing the work I did. Other benefits are that it provides new habitats for animals that have fled to other areas, like the coyote and the badger. In addition to clearing out the brush, we also planted acorns. This also helps by providing habitats for things
 like birds and squirrels. I don't that there is and downside to restoration ecology. I'm glad that we got to go out there and participate and see what good it can do. 

Spencer
When we first arrived I was amazed by how much land was at the facility and how beautiful it all was. At that point I was excited to help out with restoration of the land. When we got to the clearing of invasive species station, I didn't realize how much of the plant life was an invasive species. 
Here is me sawing down a tree (behind the giant one). Some of the invasive species we cleared included honeysuckle and buckthorn. After we cleared brush, we moved to plant acorns to help restore the natural trees. 
Here's me planting an acorn 

I believe restoration ecology is am important part of the quest to save the ecosystem because it helps restore the natural habitat, which will and is leading to native animals coming back, such as badgers. I feel like the long process is worth it in the end to see the forest look like it did before European intervention. And hopefully the work will not be ruined by invasive species coming back. 

Monday, September 16, 2013

Acids & Bases Lab

Purpose: The purpose of the experiment was to observe how different substances react to pH changes in their environment.  The dependent variable was the pH and the independent was the substances that HCl and NaOH were being added to. We were trying to find how well substances resist change to pH.

Introduction: Substances have molecules within them that react when acids or bases are added to keep the substance at a certain pH. When H+ (acid) is added these molecules called buffers dissociate to be able to accept and bond with the H+ so it doesn't affect the original substances pH.

Method: During our experiment, we would take two samples of a substance. We would add an acid(HCl) to one and a base(NaOH) to the other. We added drops of the acid/base in 5 drop increments, stirring afterwords, and used a pH probe and our LabQuest 2 to record the pH; we repeated this until there was a total of thirty drops added in total. Based on this info, we were able to determine the change of pH for each sample and a buffer range for each substance.

Data:
Our Data

Class Data
Graphs & Charts:



Discussion/Conclusion: In our experiment we tested different solutions to see what their reaction with hydrochloric acid and sodium hydroxide would be. We tested water, orange juice, antacid, and sodium bicarbonate. Orange juice and sodium bicarbonate had a bigger range when it reacted with the base. It went up higher after fewer drops making the pH go up to as high as 11 in orange juice and 9.1 in sodium bicarbonate. Water was out control group, that started as neutral and then when the acid or base was added it changed accordingly, bases making the pH go up, acid making the pH go down. The antacid also had a large range from the acids and bases at the end. As far as validity goes, we cannot be completely sure how valid all the answers were because in the experiment when we were done with one substance and changed to another, we didn’t completely wash out the beakers, we just rinsed them, so that could have contaminated it. Also, we only did one trial with all of these so there could be outliers that tampered with the experiment and changed our results, so if we had a chance to do it again we would add more trials to see if our results differed. The results of the investigation support what we thought would happen. The water changed a fair amount, but what was already acidic or basic changed even more because the hydrogen bonds are not present in these other substances, adding to a greater buffer range.