Essay About Release Of Energy And Temperature Of The Water

Respiration and Breathing System in Humans
RESPIRATION AND BREATHING  SYSTEM IN HUMANSA  Aerobic respirationRespiration is the release of energy by the breakdown of food substances in all living cells. There are two ways in which respiration can occur: aerobically, the presence of oxygen, and anaerobically, without oxygen.Aerobic respiration is the release of energy by the breakdown of food substances in the presence of oxygen. Sugar releases energy when it is combined with oxygen during oxidation. The apparatus used to show that foods release stored energy when they are OXIDISED is shown in the Figure below.                              [pic 1]The sequence of steps in this investigation is as follows:      • the temperature of the water in the test tube is recorded      • a peanut is then heated and, when it starts to burn, is held under the test tube of            water      • the temperature of the water is recorded again as soon as the peanut has stopped          burning.An increase in the water temperature shows that the peanut releases energy when it is oxidised by burning.Heat from the burner provides the energy to start the sugar reacting with oxygen. Once started, the sugar-oxygen reaction continues, with a lot of heat given off by the sugar. This form of oxidation outside living cells is called combustion.The respiration equationThis word equation summarises aerobic respiration:sugar + oxygen                carbon dioxide + water + energy [pic 2]The sugar that is normally used is glucoseThe balanced symbol equation for respiration shows how many molecules of each substance are involved in the reaction:[pic 3]The carbon dioxide and water are by-products. The reaction produces energy for the cell.Uses of energy in the bodyLiving organisms use energy released by respiration to carry outmany different processes. For example:      • to move around, in order to look for food and hide from enemies      • to obtain food and digest it      • to make your heart beat, in order to circulate blood in your body      • to speak, in order to communicate with people      • to reproduce, in order to have offspring to maintain the human population      • to keep your body warm      • to send nervous impulses from one part of your body to another part in order to             coordinate your body      • to grow      • to remove waste substances.All the energy to do these things comes from the food you eat.