On Monday, our students had the opportunity to connect with Maria and Fran at GTAC to learn about signaling molecules, insulin disorders and diabetes. Fran presented information about how molecules transmit signals across the cell membrane to allow glucose (and other substances) to be absorbed at a greater rate. Students modelled this process using paper cut-outs, showing how the message is passed from the insulin receptor, to the transmission molecules, to the effector molecules (vesicles with GLUT4 glucose transporter molecules attached), which allow more protein channels to be situated in the cell membrane. The normal response is that more glucose is absorbed by the cell, but several disorders can result in glucose not being absorbed, such as Type I and Type II diabetes. Students observed diagnostics on blood samples to determine if test patients are diabetic. They then applied the stimulus response model to learn the effect of insulin on glucose homeostasis and explore the role of insulin in cell signaling.
Image Source – a YouTube video about Cell Structure
“To grasp the reality of life as it has been revealed by molecular biology, we must magnify a cell a thousand million times until it is twenty kilometers in diameter and resembles a giant airship large enough to cover a great city like London or New York. What we would then see would be an object of unparalleled complexity and adaptive design. On the surface of the cell we would see millions of openings, like the port holes of a vast space ship, opening and closing to allow a continual stream of materials to flow in and out. If we were to enter one of these openings we would find ourselves in a world of supreme technology and bewildering complexity.” Michael Denton (1986) “Evolution: A Theory in Crisis” p328
We continue our study of cells with a look at the chemical composition of cells. Make sure you understand that cells are made up of:
- carbohydrates (monosaccharides, disaccharides and polysaccharides)
- proteins (made up of amino acids)
- lipids (made up of glycerol and fatty acids) and
- nucleic acids (DNA and RNA)
I will be at Professional Development in Melbourne on Friday, so you are asked to finish reading Chapter 3 and answer the review questions for that chapter. There are two 15 minute videos on my desk “The Living Cell” and “The Plasma Membrane”, both of which are useful for consoidating your knowledge of cells. You could also check out the resources for this chapter on the Hawkesdale Biology wiki.