3.05 The Cell: Cellular Transportation

Day 2 at Dr. Q's Dig Site

Careful, careful, we must use this beam to counter-balance this sliding door, or we won't ever get into the next vault where the treasure is. You know, it is a force of nature to seek balance. If you don't believe me fill your sink with water and slosh it around. The water always levels and calms. It doesn't get stuck in the shape of the waves you created. All of nature, both physical and biological, seeks some kind of balance, which in biology we call homeostasis.

In this activity you will: explain the function of the cell membrane compare and contrast active and passive transport relate the function of transportation in a cell to maintaining homeostasis within the cell Note: This tour will include a lab activity that takes 3 days to complete. You will need to work through the activity and set up the lab. As you collect data for 3 days you will need to move ahead to the next lessons.

Breathe!

Did you know that the reason we breathe is so our cells can take in oxygen and get rid of carbon dioxide? These gases must be able to move through the cell membrane of the cells in our lungs, and our red blood cells, to be of any use to us.

Scientists are very interested in how this movement across cell membranes occurs, so there is a lot of research taking place in this area. For example, scientists have found that people with a disease called Cystic Fibrosis have certain cells with a missing, or defective, protein in their cell membranes. This missing protein affects how salt moves across the cell membrane, so people with Cystic Fibrosis end up with salt building up outside the lung cells. As a result, their lungs become more susceptible to bacterial infections. In addition, their mucus (a lubricating fluid in various places in the body) thickens, clogging their lungs and digestive tract.

You see from this example how important correct flow of materials across the cell membrane is in maintaining balance within the cell. Oh my...there is that word again, balance. Remember, it is called homeostasis. As long as cells can maintain homeostasis, they can function normally. When cells function normally, so does the organism! Homeostasis is a set of conditions is necessary for all cell processes to occur normally.

I think I see something shiny up ahead! Is it the Pharaoh's treasure?

Move on to the BioVenture tab to find out what it is.