Human Blood

3.3 Human Blood



Human blood consists of two components, namely 55% blood plasma (pale yellow fluid) and 45% blood cells (red blood cells, white blood cells and platelets)

 The structure and function of red blood cells, white blood cells, and platelets:

The chemicals and their functions:

Chemical substance



Water becomes a transport medium and solvent for respiratory gases, ions, digestive products, and excrement

Nutrients (glucose and vitamins)

Nutrients are important in energy production, growth, and health maintenance

Dissolved gas

Oxygen is used in cellular respiration and carbon dioxide is the result of cellular respiration

Wastes substances

Wastes such as urea are transported to the kidneys for elimination


Enzymes are needed to speed up biochemical reactions in cells


Hormones are chemicals that regulate the activity of certain tissues or organs

 The blood group and suitability of blood reception:


  • Blood group O is known as the universal donor while blood group AB is known as the universal recipient

  • Blood transfusion/blood transfusion should be done according to the appropriate blood class to prevent blood collection to the recipient

The importance of donating blood:

  • Can save lives and not harm donors

  • Reduce the risk of cancer and heart disease