Thursday, November 13, 2014

Understanding Cystic Fibrosis

Cystic fibrosis is a genetic disease that primarily affects the respiratory and digestive systems. The life-threatening disease is caused when a defective gene and its protein product cause the body to produce  unusually thick and sticky mucus that can clog the lungs and obstruct the pancreas.

Symptoms of cystic fibrosis (CF) can include very salty-tasting skin, persistent coughing, frequent lung infection, wheezing, shortness of breath, poor growth, gradual weight gain (despite a healthy diet), and frequently greasy, bulky, or difficult stools. There is an estimated 30,000 children and adults diagnosed with CF in the US, 70,000 world wide. Testing for cystic fibrosis can be handled in several ways, including sweat tests, newborn screening, and carrier testing. Positive results on these tests could lead to a diagnosis for CF.

Cystic fibrosis is passed down genetically when a child inherits one copy of the defective gene from each parent. CF is a recessive gene, which means that a person must have both copies of the mutated gene in order to be affected by cystic fibrosis.


In a non-defective gene, the protein acts as a gateway, allowing ions to bring water to the surface of the airway. This keeps the mucus moist. In CF patients, the vital chloride channel is blocked, preventing the movement of chloride ions into the mucus.


This then halts the movement of water, causing the mucus to dry out. The mucus builds and begins to clog the lungs and obstruct the pancreas.



While there is no known cure for cystic fibrosis, there are several options for treatments that will reduce the symptoms and their effects. There are several medication options for CF treatment, including antibiotics, mucus-thinning drugs, bronchodilators, and oral pancreatic enzymes. Other treatment options include chest physical therapy, pulmonary rehabilitation, and surgical or other procedures.

When a child or loved one is diagnosed with CF, it is very important to care for them and offer full support. There are several ways to bring aid to a CF patient, including encouraging better nutrition, heightened fluid intake, updated immunizations, exercise, and hand washing. It is also vital to illuminate smoke from the patient's surroundings, as it will only irritate the respiratory tract and increase the issue. 

Tuesday, November 11, 2014

Osmosis Lab Report

Objective:
A lab partner and I created this experiment in an attempt to model osmosis, the traveling of molecules of a solvent across a semipermeable membrane in an attempt to equalize the concentrations on both sides of the membrane.

Procedure:
To model the process of osmosis, we set up several beakers that contained water, dialysis tubing, and a salt solution. Each was modeled differently, depending on where the salt was located. Each beaker is detailed below:


Beaker A: Dialysis tubing filled with water sealed inside, tinted with food coloring, surrounded by a salt solution.
Beaker B: Dialysis tubing filled with a salt solution sealed inside, surrounded by water, tinted with food coloring.
Beaker C: Dialysis tubing filled with solid salt sealed inside, surrounded by water.
Beaker D: Dialysis tubing filled with carbon dioxide sealed inside, surrounded by water.


Before placing the dialysis tubing in the beakers, we measured the mass of each tube after they had been filled with their solutions/contents. 24 hours later, we measured again so that we could track the movement of the water.

Claims:
It can be concluded that the water diffused to areas of higher concentrations, such as the ones that contained high amounts of salt.

Evidence:



The graph organizes the results from the experiment, proving the water traveled from areas of lower concentration to areas of higher concentration. Based on the contents of the beaker and dialysis tubing, the ending mass of the tubing varied in proportion to the movement of the water.

Research:
In a similar experiment conducted using potatoes instead of dialysis tubing, the same general results were found. The same general results were also found when using eggs instead of potatoes or dialysis tubing. When experimental results were explored during a class session, it could be concluded that all experiments yielded similar results.

Reflection:
Reflecting on this experiment, I am very satisfied with the results. Throughout the process, I was able to understand the reasoning behind the results and predict what would happen. I believe the experiment could be improved by trying to reverse the experiment. Would placing the dialysis tubing (after the first 24 hour testing period) into new beakers with different concentrations reverse the original direction of the water? It would be interesting to try to control the flow of the water through several different tests.

Wednesday, November 5, 2014

Diffusion Lab Report


Questions:
The goal of this experiment was to model how a cell membrane functions. This includes what types of substances are able to pass through the membrane, and how the membrane passes them through to the inside of the cell.

Procedure:
For this experiment, dialysis tubing was used to model a cell membrane. The tubing was filled with a glucose and starch solution, then tied at each end. The mixture was used to model the inside of the cell. The "cell" was then placed in a beaker that was filled with a iodine/water mixture. After 24 hours,  the solutions in the beaker and dialysis tubing were tested for the presence of glucose and starch. The presence of glucose will be tested using indicator strips; the presence of starch will be tested based off of the chemical reaction indicators between the starch and iodine. Starch forms a blueish black complex with iodine whereas glucose does not react.

Claims:
Based off of the results from the procedure, it can be determined that the starch remained inside the dialysis tubing, and the iodine diffused into the dialysis tubing. While some glucose diffused into the beaker, the inside the tubing also tested positive for containing traces of glucose. The water diffused into the tubing until it could not contain any more. The results of the experiment proved that molecules move from regions of higher concentration to lower concentration during diffusion. 

Evidence:
The following table displays the results drawn from the experiment that support the previous claim.

"+" represents a positive test, "-" represents a negative test


Solution Color
                                  Initial Contents                  Initial            Final           Initial        Final
     Bag          15% glucose, 1% starch         milky white         black             +             +  
    Beaker           H2O+IKI                         yellow/brown       yellowish       -              +

It can be concluded from the evidence in the chart that the glucose diffused into the beaker and the iodine diffused into the dialysis tube.

Research:
When compared to results drawn from similar experiments, online information resources, and notes taken during class lectures, it can be confirmed that molecules move from regions of higher concentration during diffusion.

Reflection:
Reflecting on this experiment, the ideas and data constantly supported the results. I believe it could be improved by tracking the motion of the water to observe if it diffused.

Pictures:



Glucose strip before the experiment


Glucose strip after experiment


Dialysis tubing with starch and glucose before the experiment


Dialysis tubing with starch and iodine after the experiment