CYSTIC FIBROSIS - A DISORDER OF MEMBRANE TRANSPORT
A great variety of proteins have roles in moving molecules and ions across cell membranes. Passive transport proteins permit certain substances to diffuse down concentration gradients by moving through the protein's interior. Active transport proteins use ATP energy to pump substances across the membrane against their concentration gradients. To investigate the importance of transport proteins, we will consider the effects of cystic fibrosis, a genetic disorder in which there is a defect in a transport protein..
Activity
Part 1.
In this part of the activity you will visit the Cystic Fibrosis Foundation’s web site to learn about the causes and symptoms of cystic fibrosis.
Use the information provided in the “About cystic fibrosis” section to answer the following questions:
1. What are the signs and symptoms of cystic fibrosis?
~very salty-tasting skin~persistent coughing, at times with phegm
~frequent lung infections
~wheezing or shortness of breath
~poor growth/weight gain in spite of a good appetite
2. How common is this disorder?
Around 1,000 new cases of CF are diagnosed each year. Approximately 30,000 people in the United States have Cystic Fibrosis.
3. How is cystic fibrosis diagnosed?
Most people are diagnosed at birth with a newborn screening, or before the age of two. Doctors who see symptoms of CF order a sweat test. The sweat test is a genetic test that confirms diagnosis.
4. How is cystic fibrosis inherited? Does everyone who has a mutant gene for the protein have cystic fibrosis?
To get Cystic Fibrosis the child must inherit two copies of the defective CF genes, one from each parent. If both parents are carriers of the genes their child will have a 25% chance of inheriting both genes, a 50% chance of being a carrier, and a 25% chance of not having CF or caring the gene.
To get Cystic Fibrosis the child must inherit two copies of the defective CF genes, one from each parent. If both parents are carriers of the genes their child will have a 25% chance of inheriting both genes, a 50% chance of being a carrier, and a 25% chance of not having CF or caring the gene.
Part 2.
In this part of the activity you will read an article to learn more about cystic fibrosis.
Use your browser to go to:
Use the information in this article to answer the following questions:
1. Explain the normal function of the protein that is defective in cystic fibrosis.
The normal function of the protein that is defective in cystic fibrosis is
Normally, the movements of the ions brings water the surface of the airway. This water keeps the mucus moist . So, the normal proteins function is to control the amount of chloride ions to the cells. This protein is named CF trans membrane regulator (ion channel)The normal function of the protein that is defective in cystic fibrosis is
2. What happens to this protein in CF patients and what are the consequences for the health of these individuals?
The defective protein means that the protein is no longer regulating the amount of chloride ions in the cells. Causing blockage in the channels and drying out of the mucus.
Part 3.
In this part of the activity you will read about how cystic fibrosis is treated.
Use your browser to go to:
Use the information in the different sections of the article to answer the following questions:
1. Explain at least 3 treatments for the symptoms of cystic fibrosis.
Three treatments for Cystic Fibrosis are all medications, since there are no cures. They are antibiotics, mucus-thinning drugs, bronchodilators. The antibiotics are used to prevent lung infections and can be taken as a pill, inhaled, and many other ways. The mucus-thinning drugs reduce the mucus’s stickiness making it easier to cough up and easier for the lungs to function. The bronchodilators are inhaled and keep the person’s airways open making it easier to breath.2. Discuss at least 3 ways for parents to help their children who have cystic fibrosis.
