| Definition | 
		
			| 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 | Function | 
		
			| Water | 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 | Enzymes are needed to speed up biochemical reactions in cells | 
		
			| Hormones | 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: