WJEC GCSE Biology/Biology 2/Respiration

There are two categories in which respiration can be classified into. 1. EXTERNAL RESPIRATION 2. INTERNAL RESPIRATION or CELLULAR RESPIRATION External Respiration It involves the inhaling and exhaling of air coupled with the human respiratory system. All the contraction and extension of the inter-coastal muscles can fit into this class of respiration. The composition of the air inhaled and the air exhaled must also be taken into action in this area of respiration. Internal or Cellular respiration It is defined as the breakdown of glucose in to release carbon dioxide and energy. This definition is quite shallow as there are two types of cellular respiration which are aerobic respiration and anaerobic respiration respectively Aerobic Respiration is the breakdown of glucose in the presence of oxygen releasing energy, carbon dioxide and water as by-products. Anaerobic Respiration is the breakdown of glucose in the absence of oxygen releasing energy, carbon dioxide and alcohol in plants but in mammals it is lactic acid which is responsible for the sores which you feel when you sprint suddenly in your calf muscles.