Cell Communication

Purpose

The purpose of the yeast cell communication lab is to see the rate at which yeast mate. We needed to record the number of yeast at each stage of the cell cycle. We also calculated the percentage of yeast at each time point and we recorded our data. We had three cateroiges to record. They were the alpha culture, the A culture, and the mixed culture. We were looked for single haploids cells and building haploid cells.

 

Introduction

Well to introduce this lab, its cell communication. The definition of cell communication is indepth in biophysics and biochemistry to identify different types of communication methods between living cells. Some of the methods include cell signaling. This lab had a focus on cell communication. Cell communication happens between cells when cells secrete chemicals to attract other cells. Cells are able to communicate by direct contact, local or long distance signaling. 

Method

In our lab, we cultured yeast in both solid and liquid mediums. The purpose of this lab was to determine how cells communicate with each other. We concluded that yeast cells cannot swim to other cells to communicate with them. We tested production of offspring during the time increments of 5, 10, 15, and 20 minutes that we set for each sample. A type, Alpha type and Mixed type were placed in their own solid and liquid mediums. They were then placed in an incubator overnight and then the amount of yeast cells were counted. 

This picture shows how we set up the lab. We have a dish for each culture.

We take a swab from the dish.

This is a look at the yeast after a twenty-four hour period.

Discussion

This experiment tested the communication in different types of yeast cells, Alpha type, A type and Mixed type. The only difference between these types of yeast cells are the different genes each specific yeast cell contains. Cell communication happens between cells when cells secrete chemicals to attract other cells. Cells are able to communicate by direct contact, local or long distance signaling. The cells use signal transduction pathways to signal one another. Each cell sends out a signal to adjacent yeast cells letting them know they are ready to mate. If the other cells are able to accept this then the receiving cell accepts the signal, brings it into the cytoplasm where the signal causes a change in the cell that makes it move towards the other cell. Our data showed that after a certain time frame the yeast cell communication slowed down and their ability to reproduce and divide slowed. 

Conclusion

From this lab we learned and got to see yeast mate. Not only did we see them mate, but our lab group saw cell communication. These yeast cells communicated and made a way to reproduce. This lab allowed us to really look hard and exam and determines the routines of how yeast mates in alpha culture, a culture, and mixed culture. The difficulties of this lab were try to capture the images of what we viewed from the microscope. The lab is considered a success because we successfully mated the yeast and took pictures of them as they reproduced.

References

"Cell Communication (definition)." Cell Communication (definition). N.p., n.d. Web. 12 Jan. 2015.

"Cellular Communication (biology)." Wikipedia. Wikimedia Foundation, n.d. Web. 12 Jan. 2015. "LabBench." LabBench. N.p., n.d. Web. 12 Jan. 2015.

Photosynthesis

Purpose

This photosynthetic experiment required us to create different mixtures involving phosphate buffer, distilled H2O, DPIP, and then adding either boiled or unboiled chloroplasts. With DPIP and the varying forms of chloroplasts we tested how fast or if photosynthesis was able to occur, and if photosynthesis was able to occur it simply reduced DPIP into the mixture. By doing this we could also track the percentage of transmitance and absorption with the help of a Colorimeter. 

Introduction

DPIP is used in place of NADP in photosynthesis so if photosynthesis does occur, meaning light does enter the chloroplast and excites the electrons to the electron acceptor, DPIP will reduce from it's blue state to a colorless state. This means photosynthesis did occur allowing the spinach cells to create energy. However, if the mixture remained blue after being exposed to light it means that the chloroplasts were damaged and unable to execute light absorption and thus DPIP remained unaltered. 

Method

We created various mixtures pertaining phosphate buffer, distilled H2O, DPIP and then either no chloroplasts for the control group or the tests which included boiled or unboiled chloroplasts. We added the chloroplasts only  after we poured the solutions into cuvettes which were immediately placed into front of a light source dispersed by a flask of water. We then took measures of light transmitance and absorption of the cuvettes using the Vernier colorimeter. 

Picture /\: Colorimeter

Graphs and Charts

Conclusion: in this pigments and photosynthesis lab we butchered the results. We made the mistake of not placing the unboiled chloroplast until after setting up the test tubes. Which caused us to remake the test tubes. Also we messed up by not placing each of the cuvettes in front of the light at the same time. The cuvettes had been in the light for different amount of times. We had to redo that part to get correct results. We placed each one with same time. The final results were correct and completed this lab making it a success. 

Reference: 

AP Bio Lab 4 - Plant Pigments & Photosynthesis." Bozemanscience. N.p., n.d. Web. 08 Dec. 2014

College Board." AP Central. N.p., n.d. Web. 08 Dec. 2014

LabBench." LabBench. N.p., n.d. Web. 08 Dec. 2014

Photosynthesis." - Wikipedia, the Free Encyclopedia. N.p., n.d. Web. 08 Dec. 2014

Cellular Respiration

Purpose: 

The purpose of this experiment was to compare and contrast the products of cellular respiration, or in other words to measure the levels of CO2 produced. We measured the production of CO2 of glass beads (control group), dormant yellow and green beans/peas and germinating yellow and green beans/peas.

Introduction:

All cells whether they are plant or animal ones undergo a form of producing energy to fuel their organism. In animal cells this is called cellular respiration and in plant cells this is referred to as photosynthesis. Each of these processes' main goal is to produce ATP (Adenosine TriPhosphate) in order to give energy to its organism. However in each of these processes which have smaller sub parts there are various byproducts that are created like CO2. So if you would be able to track the amount of CO2 produced you can determine whether a system/organism or cell is living and growing.

Method:

We took each independent variable, whether it was the control group-the glass beads, dormant peas/beans and the germinating peas/beans placed them into an air tight chamber. We let conditions inside the chamber settle down (waited for about a minute) and then proceeded to begin measuring the CO2 levels for about a minute as well, and then created our graphs and charts.

Graphs:

Conclusion: 

​At the end of this experiment, it can be determined that plant cells respire as well as photosynthesize. The Vernier CO2 sensor is used to determine whether there is CO2 released or not. This was demonstrated the day before the lab when we were told to use glass marbles in the chamber. As you can see from our data, both the room temperature container and cold temperature container showed a dramatic change of color. What it shows is that the peas were releasing CO2. The question is why? The answer is that plants respire when germinated more than the non germinated. Plant cells contain mitochondria just like in humans so plants use the mitochondria to create energy as well. They use this energy for cellular functions and keep the plant stable. Therefore, a plant could not live without respiration.

References:

 Reece, Jane B. "Cellular Respiration and Fermentation, Photosynthesis." Campbell Biology, AP Edition. Boston, M.A.: Pearson Education/Benjamin Cummings, 2011. N. pag. Print.

Enzyme Catalysis Lab

The purpose of this lab was to observe and understand the effects of changes in temperature, pH, enzyme concentration, and substrate concentration on the reaction rate of an enzyme-catalyzed reaction. Another purpose of the lab was to explain how environmental factors affect the rate of enzyme-catalyzed reactions.  Catalase is found in all organisms that use oxygen for their metabolism.  The enzyme is found in high concentrations in a organelle in cells called the peroxisome.  One of the functions of catalase is to prevent a toxic gathering of hydrogen peroxide in cells.  It catalyses the conversion of H2O2 to H2O and O2.  H2O2 is a by-product of metabolic processes.  It is usually produced in peroxisomes when they partially oxidize fatty acids.   When catalase is not there, the reaction it catalyzes is spontaneous, but at very low rates that are not able to reduce the harmful effects of hydrogen peroxide.

Data

Graphs and Charts

Discussion

The lab showed that the shorter the amount of time catalase spent eating away at the hydrogen peroxide the more the catalase hydrogen peroxide solution used up KMnO4 before it turned a slight hue of pink. Unfortunately our results may not have been accurate considering the first three values show a dramatic decrease, then followed by a higher forth value which causes a valley in the graph. The rest of the data points show a gradual decline in the amount of KMnO4 used as the length of the reaction time increased. So our lab did show an inconsistency from the reaction that lasted a minute, which skewed our data. However, ignoring this single plot point the rest of our data supports the statement that the longer the catalase was able to react with the hydrogen peroxide the less potassium permanganate was required to cause or emit a slight pink hue change in the solution. So in conclusion, the results of the lab support and prove what they should. How we collected data for enzyme activity, catalaseactivity, and base line assay is proven correctly. The lab is considered a success. The data we collected give the correct numbers or gave a number that is very close. The only time numbers were a little off were in the case of reading the burette when titration. The reading of the initial and final were important because it effected the percentage of spontaneously decomposes and the base line. The lab was done correctly and had right results.

 

 Reference:

"Enzyme Catalysis." Wikipedia. Wikimedia Foundation, 11 Feb. 2014. Web. 09 Nov. 2014.

"Enzymes Are Catalysts." Enzymes Are Catalysts. N.p., n.d. Web. 09 Nov. 2014.

"LabBench." LabBench. N.p., n.d. Web. 08 Nov. 2014.

"The Mechanism of Enzyme Catalysis." The Mechanism of Enzyme Catalysis. N.p., n.d. Web. 09 Nov. 2014.

Diffusion Osmosis Lab

Lab 1A:

The purpose of experiment part 1A was simple, to measure diffusion of small molecules through dialysis tubing. Dialysis tubing is a type of semi-permeable membrane tubing[1] used in separation techniques that facilitates the removal or exchange of small molecules from macromolecules in solution based on differential diffusion. In the context of life science research, dialysis tubing is typically used in the sample clean-up and processing of proteins and DNA samples or complex biological samples such as blood or serum. Dialysis tubing is also frequently used as a teaching aid to demonstrate the principles of diffusion, osmosis, Brownian motion and the movement of molecules across a restrictive membrane.

The initial purpose of lab 1A was to measure the diffusion of small molecules through the selectively permeable dialysis tubing. My group concluded that the glucose was able to leave the tubing. 

1B

Lab Part 1B

Purpose: We set out to discover the relationship between solute concentrations, selectively permeable membranes and the way they react with osmosis. 

Introduction: Osmosis is the movement of water from a high concentration to a low concentration, trying it’s best to reach equilibrium. When or if the concentration outside of the membrane is more concentrated compared to the inside of the membrane, water will move out to even the concentration out. Selective permeability refers to the ability of that cell or objects to decide what can and cannot enter but either way it always unsuccessfully striving to reach equilibrium with its surroundings.

Methods: We tied up six presoaked dialysis tubing bags and filled them up with the following concentrations of sucrose:

a)   Distilled water

b)  0.2 M sucrose

c)   0.4 M sucrose

d)  0.6 M sucrose

e)   0.8 M sucrose

f)    1.0 M sucrose

After that we placed each of the bags in their own cups filled with distilled water for half an hour and then took them out and recorded their new or final masses.

Data, Graphs and Charts:

Discussion: The data shows a consistent trend between the group and class data until it gets to the 6^th where our data differs dramatically from the rest of the class undoubtedly from an error. Otherwise the data would not have jumped from the class average of 9.69 to ours of -2.174. That much difference in percentage change is very extreme. But for the rest of the experiment our data is very useful because it is around the norm but since we had one abnormal point the rest must also be assumed to be faulty and cannot be taken into consideration. 

1C

Purpose: The purpose of the lab was to fully understand the concept water potential. Our job was to use potato cores, and place them in different molar concentrations of sucrose in order to determine the water potential of potato cells. We wanted to see what would physically happen to potato cores. The independent variable is the potato cores and molar concentrations. The dependent variable is the physical outcome of the potato cores features after laying in a high or low molar concentration. We were really trying to find out the size and weight of the cores after the concentration.
Introduction: Intro into this lab is water potential. The definition of water potential is potential energy of water relative to pure water in reference conditions. Water will always move from an area of high water potential to an area of lower water potential. Water potential can be affected by 2 physical factors. Which are the addition of solute which lowers the water potential, and pressure potential with is physical pressure.
Methods: To start the lab we had to cut up 3 cores of potato for each cup that contained a certain amount of concentration. The potato cores had to be congruent to each other. We placed 3 cores in each cup. Then we covered the cups, and let them stand over the night. The next day we uncovered the cups and took the cores out of the cups. We weighed the cores. The lower the concentration the heaver the potato cores weighed. As we got to a higher concentration the lighter the cores were. The physical outcome of the core was that the more concentration the more fragile the cores were.

This graph show the class average versus our group data of the sucrose amount and the mass of potato cores.
Discussion: From looking strictly at our data chart it shows the initial mass of the potato cores, and then the final mass. The first row was with no sucrose, just distilled water. Then next column started with 0.2,0.4 ,0.6, 0.8, and 1.0 molar sucrose. We predicted that the potato cores that stayed in a high concentration would have a higher percent of change in mass than a low concentration. As you can observe, the mass of the potato cores with a low concentration had a higher final mass compared to higher concentration. Then the mass of the potato cores with a higher concentration had a lower final mass. So we hypothesized correctly what would happen to the masses of the potato cores in a high and low concentration. The percentage of change in mass started off with positive percentage then as the sucrose level got higher the percentage became negative. The percentage getting as high as 36.84%. One trend we notice was that in distilled water and 0.2 sucrose the final masses were higher than their initial mass. Looking back on the experiment I don’t think there is any invalidity on this trend. This experiment was considered a success because we correctly tested what we wanted to learn. Also we got the results we wanted and predicted. The results support our hypothesis.
 Conclusion: The end result of the lab was that if there was enough solute is added to the water outside the cells, water will leave the cells. This means moving from an area of higher water potential to an area of lower water potential. When cell losses water it will cause lost of turgor. Loss of water continuously will cause the cell membrane to shrink away from the cell walls. The data we recorded of the potato weight showed a decline in weight from a high molar concentration. The data concludes that we did the experiment right.

Reference:
"LabBench." LabBench. N.p., n.d. Web. 22 Oct. 2014.

"Water and Solute Potential Boundless Open Textbook." Boundless. N.p., n.d. Web. 25 Oct. 2014. 
 "Water Potential." Wikipedia. Wikimedia Foundation, 10 June 2014. Web. 24 Oct. 2014. 

1E

Discussion: From this lab the results we got described the effects of high concentrated solutions on diffusion and cellular contents. Only the definition of plasmolysis helped this experiment. This is shrinking of the cytoplasm of a plant cell in response to diffusion of water out of the cell and into a hypertonic solution surrounding the cell. The description of what the wet mount small piece of epidermis on the onion looked like is a very clear cell membrane. Then the drops of 15% NaCl makes the picture look completely different. Then results of the lab were good and correct. We properly did this experiment and the results are fitting. The validity of the experiment is correct proving that the experiment was a success.

 Reference:

-"Microscopy." Microscopy. N.p., n.d. Web. 26 Oct. 2014.

-N.p., n.d. Web.

-"Plasmolysis of Red Onion Cells." MicrobeHunter Microscopy Magazine. N.p., n.d. Web. 26 Oct. 2014.

-"Plasmolysis." Wikipedia. Wikimedia Foundation, 16 Oct. 2014. Web. 26 Oct. 2014.

- Video taken from YouTube

- Picture from Google Images

Milk Lab :-)

Percentage of Protein Present in Skim Milk

A Scientific Investigation by,

Waylan Washington & Max Thalhammer

The purpose of this experiment was simple, the purpose was to find the percentage of protein present in skim milk. We tested the concept that when you curdle milk with acid, and separate the curds from the liquid, you can find the true percentage of protein in skim milk. Skim milk is filled with protein and has more than 40 percent less calories than whole milk. Your body relies on more than 20 individual amino acids to support basic bodily functions. Skim milk is an excelent source of protein, because it supplies all of the essential amino acids you need. While skim milk is an excellent protein source, there are other components that make it unhealthy in large quantities. In the lab, we took a small sample of skim milk and added concentrated acetic acid. Adding this acid caused the milk to curdle. After the milk sat curdling for about five minutes, we folded a coffee filter into a funnel, and used it to filter out the acid from the protein. From that point, we set the wet filter into a box to dry overnight. When we received the dried filter the next day, we immediately massed the filter, and started making calculations. The table shown below has our masses for the filter, the dry protein plus the filter and just the protein itself. 

The milk analysis lab in our group’s eyes is viewed as a success. Our group proved, and provided the data to show the percentage of protein in non-fat milk. Also we compared it to the value print on the container. On our first day of the lab our group carefully followed the procedures, and found some trends of the lab. When we added 30 drops of concentrated acetic acid to the milk and we let the milk sit for a few minutes. The milk started to form curds. The acid denatures and coagulates the milk protein, forming these curds. Milk curds due to the pH drops and becomes more acidic , the protein molecule attracts one another and becomes curdles floating in a solution of translucent whey. It smells bad because a high level of lactic acid gives its sour smell.  Our lab group found it important to find the percentage of calories in the non-fat milk due to protein, which is 51%. This percent is a very realistic answer, causing our group to view this as good and valid. The worst part of the lab was pouring the coagulated milk into the funnel.  Then removing the filter paper and placing it in a massed Styrofoam cup  with some paper towel packed into the bottom to absorb any liquid. This part was the worst because the process of waiting took too long. This caused a dislike to the lab. Our group had to test to see if protein was present. So we took a water test tube and the milk filtrate tube and added 1 mL of biuret reagent to each tube. We looked for the tube with a purple or bluish color to determine if protein is present. Protein was present in the milk filtrate but not the water tube.To be honest the results of this experimental lab support what we though the outcome would be. Although we had some flaws and unorganized parts and view of this lab, it was a true success. We finished the lab and found out the percentage of protein in non-fat milk, and the percentage of the value printed on the container. Also we calculate the percentage of calories in the non-fat milk. This lab was not only a success but also very fun and taught us much. The purpose of the milk analysis lab was to find out the percentage of protein in non-fat milk in 15mL carton. Then compare it to the value printed on the back of a carton of non-fat milk. My lab group found out that there is .77grams of dry protein in a 15mL of non-fat milk. We compared that .77 grams to the 8 grams of protein a full carton of non-fat milk. The difference is 7.23 grams of protein. The data that my lab group gathered showed the correct amount of protein collected in one carton of non-fat milk.

Citations:

Coffman, Melodie A. "How Much Protein in a Serving of Skim Milk?" Healthy Eating. Demand Media,                   n.d. Web. 23 Sept. 2014.

"Casein." Wikipedia. Wikimedia Foundation, 22 Sept. 2014. Web. 23 Sept. 2014.

"How to Make Yogurt." How to Make Yogurt. N.p., n.d. Web. 23 Sept. 2014.

"Nutrition Facts." And Analysis for Milk, Fluid, Nonfat, Calcium Fortified (fat Free or Skim). N.p., n.d. Web. 23 Sept. 2014.

"Skimmed Milk." Wikipedia. Wikimedia Foundation, 09 Mar. 2014. Web. 23 Sept. 2014.

"Why Does Milk Curdle -- and When Is It a Good Thing?" About. N.p., n.d. Web. 23 Sept. 2014.