Cystic Fibrosis Research

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 your browser to go to http://www.cff.org/home/
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 phlegm;

frequent lung infections;

wheezing or shortness of breath;

poor growth/weight gain in spite of a good appetite; and

frequent greasy, bulky stools or difficulty in bowel movements.

2. How common is this disorder?

About 1,000 new cases of cystic fibrosis are diagnosed each year.

More than 70% of patients are diagnosed by age two.

More than 45% of the CF patient population is age 18 or older.

The predicted median age of survival for a person with CF is in the late 30s.

3. How is cystic fibrosis diagnosed?
Most people are diagnosed as babies, or before the age of 2 through screening. A sweat test (the more commonly used test) or a genetic test with be performed to determine whether or not it is there.

4. How is cystic fibrosis inherited? Does everyone who has a mutant gene for the protein have cystic fibrosis?

One protein is different for that person. They have inherited two copies of the defective gene. One can have the CF gene, but that does not necessarily mean that they have CF.

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:
http://resources.schoolscience.co.uk/MRC/3/page3.html
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.
This gene will typically show up in the epithelial cells that line the airways of the lungs. There are channels for those cells that allow ions to flow in. This brings the water to the surface and keeps mucus moist. The gene will prevent those from getting moist, leaving them all dried out. This makes it easier for those people to get infections. They need some extra care for that!

2. What happens to this protein in CF patients and what are the consequences for the health of these individuals?
Movement of chloride ions into the mucus are cut off. Sodium ions are allowed to then flow into the cell, allowing it for drying out more. Bad news! That person is then prone to infection.

Part 3.

In this part of the activity you will read about how cystic fibrosis is treated.
Use your browser to go to:
http://www.mayoclinic.com/health/cystic-fibrosis/DS00287
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.
Medications, chest therapy, organ function tests

2. Discuss at least 3 ways for parents to help their children who have cystic fibrosis.

Healthy eating, exercise, and drinking lots of fluid would be great ways to help support and keep their child healthy!

Cell Membrane Notes

The plasma membrane is common to all cells
Separates:
  Internal living cytoplasmic from
  External environment of cell
Phospholipid bilayer:
  External surface lined with hydrophilic polar heads
  Cytoplasmic surface lined with hydrophilic polar heads
  Non polar, hydrophobic, fatty-acid tails sandwiched between

MEMBRANE MODELS
Fluid-Mosaic Model
Three components:
  Basic membrane referred to as phospholipid bilayer
  protein molecules
    float around like icebergs on a sea
    Membrane proteins may be peripheral or integral
      Peripheral proteins are found on the inner membrane surface
      Integral proteins are partially or wholly embedded (transmembrane) in the membrane
    Some have carbohydrate chains attached
  Cholesterol

How does it do its job?
How does it let stuff through?

It's like a perfume being sprayed. Once the particles get into the air, they spread out more. That's why people across the room can smell just one spray of perfume!

Diffusion: Movement from high concentration to low concentration

Osmosis: diffusion of water across a membrane

What CAN go across a cell membrane WILL go across!

When it is warmer, the molecules move faster. So when it's colder, they must move slower and it's tougher for them to move around.

My Macromolecules in Cells Web Activity

Web Activity: Macromolecules in Cells

Open your web browser and navigate to:

http://www.sci.uidaho.edu/bionet/biol115/t2_basics_of_life/lesson2.htm

Read the introduction to Macromolecules and answer these questions:

1. What is a macromolecule?

Macromolecules usually refer to a large group of molecules.

2. What is a monomer?

A monomer is something (one) that can be combined with other monomers to create polymers.

3. What is a polymer?

A polymer (multiple) is many monomers joined together.

4. List the four main types of macromolecules.

The four main types of macromolecules are proteins, lipids, carbohydrates, and nucleic acids.


In the learning materials box click the link for the activity “making and breaking polymers.”  Use this activity to help answer the following questions:

5. What are the types of reactions that macromolecules are shown to undergo?

Dehydration synthesis (condensation), and hydrolysis reaction (breaking down covalent bonds).

6. Describe how monomers are joined together.

Monomers might be made of sugars or like substances, allowing them to become linked together by the dehydration process.

7. Describe how polymers are broken down.

An addition of a water molecule breaks

8. What is the specific name for the bond between simple sugar monomers?

Dehydration synthesis (condensation).

9. Which kind of enzyme joins monomers together?

Covalent bond


Back on the previous macromolecules page, scroll down to the section on carbohydrates. In the learning materials box for carbohydrates click the link to the “build a carbohydrate” activity.

10. Describe how you had to arrange the sugar monomers in order to build a polysaccharide.

I had to move a monomer to match up with the certain elements on the other monomers to bond together and create the polysaccharide. A little water drop formed (probably meaning condensation), and the two bonded. Very neat!

11. Which building blocks of macromolecules are not used in building carbohydrates?

Nucleotide, Fatty Acid, and Amino Acid.

Back on the previous carbohydrates page, click on the link on the bottom of the page labeled “More on Carbohydrates.”  Read the article and answer these questions:

12. Why is sugar stored as glycogen in the human body?

Sugar is stored as glycogen in the human body for it to break down and absorb energy from.

13. Why are plant foods essential to animal life?

Those plant foods have sugar in them, which are also pretty good for giving energy.

14. Describe how starch is digested by animals.

Begins in the mouth with salivary amylase (spit), continuing in the small intestine with pancreatic amylase (stomach acid).

15. What is “fiber” and why is it important in your diet?

Carbohydrate polymers. It's important to your diet because it helps in absorption or neutralization of toxicity or other foods. Pretty much, it saves you from frying because of what you ate. AND it's great for the bowels! Keeps from getting bowel/colon cancer.

16. What causes you to pass gas (fart) according to the article?

Undigested protein and putrefaction cause this to happen. Protein-carbohydrate balance is important here. Stinky gas means you're eating bad. But if your farts don't stink (but there's no way they're gonna come out smelling like roses, so don't expect that!), then you can know that you're eating good and should keep it up!

Scroll back up to the top of the carbohydrates article and click on the link in the text to “Low Carbo Madness” and read the linked article. (or click here)

17. What are some disadvantages of a low-carb diet?

Your body must have approximately 45% to 65% of what it eats to be calories from carbohydrates in order to maintain function.



Return to the original carbohydrates lesson page and click on the link on the bottom “Carbohydrates and Cavities” and read the linked page.

18. Describe the role that sugars play in cavity formation in your teeth.

acid-producing bugs, carbohydrates, and teeth. These add up to cavities. Some preople don't have enough acid in their mouth produced in order to break down certain foods, so they sit in their teeth and rot, making cavities form.