Friday, November 19, 2010

Cell Structure

After looking at many diagrams of cells I learned some specific parts of the cell.  If you follow the link you can see my Glog about cell structure! (click the word Glog) :)

Monday, November 15, 2010

Cystic Fibrosis :/


Many people don't even know what Cystic Fibrosis is, but at the same time, many people of all ages are being diagnosed every year.  Cystic fibrosis is a long-term disease that takes a toll on the lungs and digestive system of about 30,000 children and adults in the United States alone.  Overall there are around 70,000 diagnosed around the world.  In CF, a defective gene and its protein product cause the body to make unusually thick, sticky mucus that plugs up the lungs and can lead to fatal lung infections, and it also obstructs the pancreas and prohibits natural enzymes from assisting the body in breaking down and absorbing food.  In the 1950s, very few children lived to go to elementary school if they had cystic fibrosis.  Advances in research and medical treatments have further enhanced and extended life for children and adults that had CF.  Many people who are diagnosed with this deadly disease can now live into their 30s, 40s or older.  About 1,000 new cases of CF are diagnosed every year, and more than 70% of patients are diagnosed by the time they turn two.  However, more than 45% of the cystic fibrosis patients are 18 or older.  Unfortunately, the predicted median age of survival for a person suffering from cystic fibrosis is in the mid-30s.  People that have cystic fibrosis can have many different symptoms which may or may not include: very salty-tasting skin; persistent coughing, with phlegm; many lung infections; wheezing or shortness of breath; little growth/weight gain in spite of a healthy appetite; and other symptoms.
In the early 1980s, researchers found that the outer membranes of cells from people with the disease are poorly permeable to chloride ions, but biochemical analysis failed to identify the defective protein.  In 1985, they pinpointed the mutation to a small region located on chromosome 7.  The final breakthrough came in 1989, when the gene responsible for cystic fibrosis was finally isolated.  This is known as one of the most significant discoveries in the history of human genetics.  It led to improving the diagnosis of the disorder and improved the genetic counseling offered to affected families.  However, CF is a very complicated disease.  Not all of the the cystic fibrosis cases are caused by the same genetic defect.  About 800 different mutations have been identified in the CF gene, which affects the proper functioning of the CFTR, which is the Cystic Fibrosis transmembrane regulator protein.  The CFTR controls the flow of chloride ions from the cell.   The picture below shows the section through the cell membrane of an epithelial cell.  The CF transmembrane regulator channel is open in the image.















Cystic fibrosis generally happens in white people of northern European ancestry, occurring in about 1 out of 3,000 child births.  In the earlier days, people with this deadly disease died in their teens.  Improved screening and treatments now allow many people with cystic fibrosis to live into their 50s or older.

Tests that can be done in a lab are newborn screening tests, sweat tests, genetic testing, sputum tests, and organ function tests.  Imaging tests can be done by x-rays, computerized tomography, and magnetic resonance imaging.  There is also a lung function test which measures the size of your lungs, how much air you can breathe in and out, how fast you can inhale and exhale, and how well your lungs deliver oxygen to your blood.

Overall, Cystic Fibrosis is a very fatal and costly disease to patients and their families.  I learned that people with cystic fibrosis have a very tough life and it makes me realize that I take many things for granted that I never even thought about, such as breathing.  People suffering from CF have a hard time doing sports and even the small things like, walking.  Cystic Fibrosis attacks your lungs and makes you hack up gross mucus and keeps young kids from doing the things that I enjoyed while I was young.  After reading about this fatal disease, I am thankful for having good health and my heart goes out to those suffering from it.

Tuesday, November 9, 2010

Cell Membranes in a Fluid Mosaic Model :)

Lately in Biology we have been learning about the cell membrane and what exactly is in the cell membrane!  The cell membrane is a phospholipid bilayer.  The phospholipid bilayer has hydrophobic tails, which means they are attracted to water.  The phospholipid bilayer also has hydrophilic heads, making them scared of water.  Inside the phospholipid bilayer there are glycoprotein, proteins, cholesterol, glycolipids, carbohydrates, and many others.  In the cell membrane there is a protein channel.  After reading the word protein channel, using common knowledge, I just thought it was a type of system that carried along proteins throughout the membrane.  Well, in scientific terms, the protein channel are cells that create and install their own protein channels which are also called membrane structure, because cells need a way to move useful substances into themselves and pump the waste outside.  The proteins act like little machines moving around other molecules.  I also learned that carbohydrate chains serve as recognition makers.  We created cell membrane posters and labeled everything that was in a cell membrane.