Cells are composed of their cytoplasm, which includes the cytosol and organelles,

the nucleus and the surrounding plasma membrane. You should know that the

plasma membrane is a double layer of phospholipid molecules and that these molecules have a hydrophilic end and a hydrophobic end. The plasma membrane contains proteins including the ATPase (the sodium-potassium pump) which moves

sodium ions out of the cell while moving potassium ions into the cell. Other proteins

act as receptors and as pores or gateways into the cell. You should know the names

and function of some of the organelles within cells. For example, you should know

that mitochondria produce ATP and that ribosomes synthesise proteins from amino

acids.

You will become familiar with the names of many cells. Often a word can be

recognised as the name of a cell because it ends in “-cyte” or, if it is an immature

cell, by ending in “-blast”. Four major types of tissue are identified in the body:

epithelial, connective, muscle and neural tissues. Of course there are many subtypes

within these categories. For example, epithelial tissue may be squamous, cuboidal,

columnar or glandular. Muscle may be skeletal, smooth or cardiac. Connective tissue is quite varied, and you should be aware of the many different examples of tissue that are categorised as “connective”. For example, blood, bone, dermis, cartilage

and tendon are all connective tissues.