PROCESSES, FUNCTIONS AND STRUCTURE OF CELLS What are the specialized structures that allow a red blood cell to carry out its role? The role of the red blood cell is to carry oxygen (in the form of h
PROCESSES, FUNCTIONS AND STRUCTURE OF CELLS What are the specialized structures that allow a red blood cell to carry out its role? The role of the red blood cell is to carry oxygen (in the form of h
PROCESSES, FUNCTIONS AND STRUCTURE OF CELLS
What are the specialized structures that allow a red blood cell to carry out its role?
The role of the red blood cell is to carry oxygen (in the form of hemoglobin) to other cells. Its structure is different from other eukaryotic cells: in order to maximize the space available for the hemoglobin it carries, the red blood cell does not contain a nucleus or mitochondria. It has a thin membrane for oxygen to get through quickly and easily and is biconcave in shape, giving the oxygen a larger surface area to diffuse in or out. It also has a flexible membrane to enable it to pass through smaller capillaries.
The cell membrane is made up of a phospholipid bilayer. This consists of two layers of lipids, each of which has a phosphate head (hydrophilic) and two fatty acid tails (hydrophobic). As the phosphate heads are water-loving, these line up in a circle on the outside, with the tails facing inwards, to create the cell membrane. Within this tight construct is found cholesterol, which regulates the fluidity of the membrane when it gets warmer or cooler.
This is very important because the pieces of the membrane must be able to float around constantly – hence the ‘fluid’ in the fluid mosaic model. A significant amount of proteins can also be found in the cell membrane. These are generally trans-membrane proteins (existing across the whole membrane), or peripheral proteins which sit on top of the phospholipid bilayer (or on top of other proteins), but