Respiration is a Chemical Reaction
Cellular respiration
- Cellular respiration is the process of transferring energy from the breakdown of glucose
- It is a universal chemical process which is continuously occurring in all living cells
- Every process happening in your body requires energy
- The energy transferred by respiration cannot be immediately or directly used by the cell
- Energy is stored in the form of a special molecule of called ATP
- ATP can then be used in cellular processes where energy is required
- An analogy of ATP is a rechargeable battery which can store potential energy and release it as kinetic energy
- Once the energy has been depleted the battery can be recharged
- Organisms need energy for:
- Chemical reactions to build larger molecules from smaller molecules
- Muscle contraction to allow movement
- Keeping warm (to maintain a constant temperature suitable for enzyme activity)
- The energy transferred supplies all the energy needed for metabolic processes to occur within cells and organisms as a whole
Uses of the energy released from respiration
- Although most of the energy generated through respiration uses glucose as a substrate, organisms can break down other molecules to be used in respiration
- Proteins, lipids (fats) and other carbohydrates can all be utilised
- Cellular respiration can either be aerobic (in the presence of oxygen) or anaerobic (in the absence of oxygen)
- Cellular respiration is controlled by enzymes, consequently the rate can be affected by temperature and pH
Aerobic Respiration
- Aerobic respiration requires oxygen
- It is defined as the chemical reaction in cells that uses oxygen to break down nutrient molecules to release energy
- Most aerobic respiration takes place in the mitochondria
- Aerobic respiration is the complete breakdown of glucose to release a relatively large amount of energy for use in cell processes and reactions
- Carbon dioxide and water are produced as waste products as well as releasing useful cellular energy
Word equation for aerobic respiration
- This equation can also be shown as a balanced symbol equation
- One molecule of glucose combines with six molecules of oxygen to produce six molecules of carbon dioxide and six molecules of water
The balanced symbol equation for aerobic respiration