.1.A piece of bread contains insoluble carbohydrates. When a human eats the bread, the human's teeth grind the bread down and the saliva softens the bread. In the saliva there are enzymes called amylases which brake down the insoluble carbohydrates into smaller soluble sugars. The soluble sugars pass down the oesophagus into the stomach and into the small intestine. When they arrive in the small intestine ,enzymes come and start to break the soluble sugars into glucose.The glucose molecules get absorbed quickly through the wall of the small intestine and into the bloodstream.
2. When in the bloodstream the glucose is dissolved into the blood plasma. When we breathe we take in the oxygen and it goes into the small air sacs which are alveoli’s. The oxygen comes from the alveoli’s and into the bloodstream. The oxygen is not absorbed by the plasma but instead carried by red blood cells. These blood cells contain haemoglobin which attracts the oxygen. 3.(A vein is when the blood goes to the heart with deoxygenated blood, an artery is where the blood is carried away from the heart and has oxygenated blood).The glucose will pass through the vein which will go up to the heart carrying deoxygenated blood and go through the right heart chamber and come out, the artery coming out has deoxygenated blood it goes through the capillaries in the lungs and goes into the left heart chamber, this is a vein which carry’s oxygenated blood. The glucose in the blood in the heart is pumped when the muscles in the walls press and the glucose in the blood comes out. The heart is not symmetrical. The left side of the heart is bigger because it has to work harder and pump the blood further while the right side only has to pump the blood to the lungs and back. The glucose molecule will also pass through the capillaries in the small intestine, and in the bloodstream to the other parts of the body. 4.The gaseous exchange is when carbon dioxide goes into the alveolus and then goes out while the oxygen from the air that has been inhaled comes into the alveolus and stays. When breathing rate is higher such in exercise more oxygen enters the lungs and can be taken up and the carbon dioxide can be exhaled more quickly. Respiration happens inside the cells of the human body. Oxygen and glucose enter into the cell from the tissue fluid and the waste products such as carbon dioxide leaves the cells, gets dissolved into the tissue fluid and goes back into the blood in another capillary, and the lactic acid sits in your cells until it breaks down.The lungs and the heart are linked because they are both part of the pulmonary system and the circulatory system. 5.When humans exercise the cells in our muscles are most likely using the aerobic respiration which is when oxygen and glucose make carbon dioxide, water and a lot of energy. When your body runs out of oxygen it uses anaerobic respiration which is when glucose has been broken down to lactic acid and a low amount of energy. The best respiration process to be using is aerobic respiration because you release a lot of energy and there is no lactic acid. Lactic acid is harmful to the human body. |