Introduction
For my coursework, I intend to assess how temperature affects the plasma membrane of a cell. For this I will use the cell of a beetroot.
Background
What is a cell membrane?
The cell membrane, also called the plasma membrane is a semipermeable lipid bilayer which is the surface of all cells that surrounds the cytoplasm. The membrane is called a bilayer as it has a double layer of phospholipids. Within the cell membrane there are many biological molecules, proteins and lipids, which are involved in cellular processes, and also serves as the attachment point for both the intracellular cytoskeleton and, if present, the cell wall. It is selectively permeable and chooses what molecules enter and leaves the cell and also maintains the cells potential.
This following picture is a diagram of the fluid mosaic with all the different molecules labeled:
Phospholipids –
Phospholipids are a type of lipids which are key parts of all biological molecules, along with glycolipids, carbohydrates and proteins.
The circular head of the phospholipid is the phosphate component. This is hydrophilic (Water Liking) therefore faces the aqueous part that surrounds the membrane. The tail of the phospholipid is the fatty acid component. This is the opposite of the phosphate as it is hydrophobic (Dislikes Water) therefore the tails point inwards towards each other as it is a bilayer forming a non-polar interior. Cholesterol-
Cholesterols are the lipids found in the membranes of all tissues. The name cholesterol comes from the Greek words chole (Bile) and stereos (solid).
The phospholipid molecule is like the cholesterol molecule in the way that the cholesterol also has hydrophilic (Water Liking) heads and hydrophobic (Dislikes Water) tails, therefore they are able to fit between the phospholipid molecules.
The cholesterol molecule helps keeps the fluidity of the