Intro to Cell Signaling

In order to understand diabetes, we learned about

• • Biomolecules, monomers
  • Their uses such as building or repairing cells and cell respiration.   
  • We get these molecules from the food we eat 
  • We break down the biomolecules to monomers and absorb them in our digestive system
  • Our bodies strive for a stable internal environment (homeostasis) 
  • A key example is a stable and consistent blood glucose level (BG)
  • This is maintained by a  negative feedback loop involving insulin, glucagon, the pancreas and liver
  • But the glucose needs to enter into cells in order to be used for cell respiration (or construction)
  • The cell membrane controls that process
  • Its phospholipid bilayer and mosaic of proteins determines that function. 
  • Specifically glucose  has to cross through a transport protein called GLUT4

Cell Communication and Cell Membranes 

Cell membranes aren't just waiting around to let molecules enter or exit. They are in communication with the cell and with the  external environment. In this case, the cell membrane is in communication with the information flowing through the blood, ie insulin and glucagon. The image below shows a cell releasing a signal and another cell receiving the signal and responding. There are many different signaling and response systems.  We are going to focus on the insulin signaling pathway. 

The GLUT4 protein doesn't sit around in the cell membrane waiting for glucose to come by. It is kept inside the cell and is sent to the membrane when there is glucose to absorb. This happens when the membrane receives this information from insulin.   In order to understand this process we need to learn about Cell Signaling 

Cell signaling

Cells receive signals (information) from the rest of their environment. That could be from another cell in their body (ie a  hormone)  or from something outside of the organism (ie light).  

Watch the videos below and then take the quiz on the following page.  I've annotated the videos with comments, cut out parts with too much detail and combined them into one video.  but if you want to watch the videos without those, you can find them by following these links

Amoeba Sisters Cell Signaling Links to an external site.

The Insulin Signaling Pathway Links to an external site. 

Insulin Signaling (Signal Pathways) Links to an external site.