Hi everyone, This week you should be looking through the notes on Unit 1 Cells and Tissues. You will see that much of the information on the cell is familiar but slightly more detailed than in Bioscience 1. The usual organelles are there but you are expected to know a bit more about their structures and functions. There are also some new structures including peroxisomes, flagella and cilia and different kinds of filaments and tubules that make up what is known as the cytoskeleton that allows whole cells, organelles and chemicals within cells to move.

The Unit then goes on to describe the structure of the plasma membrane and the various ways in which molecules pass across it. This is the part of the unit that has most new information as it describes the functions of the various different proteins in the plasma membrane. You will learn that diffusion can occur through the phospholipid bilayer, through protein channels and through gated protein channels, and that active transport can be aided by transporter proteins, co transporters or counter transporters. You will learn how receptor mediated endocytosis differs from pinocytosis and in the interactive version of the Unit one of the revision excercises asks you to match the molecule with its mode of entry into the cell.

Two other new topics in this Unit are the cell cycle and the different stages involved in normal cell divion or Mitosis. Finally the section on tissues should be pretty familiar although a few new tissues are described --pseudostratified columnar epithelium for example-- and the structures and functions of the tissues are described in slightly greater detail.

It would be great if you could get this Unit completed this week so that you can start on Unit 2, the nervous system, next week. This will allow you to come to the tutorial/practical on Friday Aug 14th with some knowledge of this system. Here I can talk about the basic structure of the neuron and the central and peripheral nervous systems but it would also be good if you can apply some of the knowledge by doing excercises that involve recognising structures on models of the nerve cell or neuron and the human brain. I have also ordered some pigs heads which have been cut in half to reveal the brain so you can observe and dissect these. Looking at a real brain and recognising the different areas and structures is a wonderful learning opportunity that is definateley enhanced by a bit of prior knowledge.

Have a good week,

Cheers Ruith