Respiration in humans

Name: __________________ Topic: Respiration in humans Concepts Summary Notes Nan Hua High School Biology 1 LO: I dentify on diagrams and name the larynx, trachea, bronchi, bronchioles, alveoli and associated capillaries LO: State the characteristics of, and describe the role of, the exchang e surface of the alveoli in gas exchange Adaptations of alveoli for gaseous exchange: ● Numerous alveoli provide a large surface area for gaseous exchange. ● Alveolar walls are one cell thick, allowing for faster diffusion of gases. ● Thin film of moisture on the inner surface of the alveoli allows oxygen to dissolve in it. ● Walls of the alveoli are richly supplied with blood capillaries. The flow of blood maintains the concentration gradient of gases.

Name: __________________ Topic: Respiration in humans Concepts Summary Notes Nan Hua High School Biology 2 LO: Describe the removal of carbon dioxide from the lungs, inc luding the role of the carbonic anhydrase enzyme At the body cells/ tissues: ● Carbonic anhydrase, an enzyme found in red blood cells catalyses the conversion of carbon dioxide and water to carbonic acid. Carbonic anhydrase carbon dioxide + water → carbonic acid CO2 + H2O → H2CO3 ● Carbonic acid is converted to hydrogen carbonate ions which diffuse out of the red blood cells. ● Most carbon dioxide is carried in the blood plasma as hydrogen carbonate ions. In the lungs: • Carbonic anhydrase found in red blood cells catalyses the conversion of carbonic acid back to carbon dioxide and water. Carbonic anhydrase carbonic acid → carbon dioxide + water H2CO3 → CO2 + H2O ● Carbon dioxide diffuses out of the blood capillaries into the alveoli to be removed during exhalation.

Name: __________________ Topic: Respiration in humans Concepts Summary Notes Nan Hua High School Biology 3 LO: Describe the role of cilia, diaphragm, ribs and intercostal muscles in breathing Cilia Diaphragm Ribs Intercostal muscles Found on the epithelial cells which sweeps and remove mucus Goblet/gland cell produces and secretes mucus Inspiration: Diaphragm muscle contracts and flattens to increase volume of thoracic cavity and lungs expand. Pressure in lungs decrease and air is forced into the lungs. Expiration: Diaphragm muscle relaxes and arches upwards to decrease volume of thoracic cavity and lungs contract. Pressure in lungs increase and air is forced out of the lungs. Inspiration: Swings upwards and outwards to increase volume of thoracic cavity. Expiration: Swing downwards and inwards to decrease volume of thoracic cavity. Inspiration: External intercostal muscles contract while the internal intercostal muscles relax Expiration: Internal intercostal muscles contract while the external intercostal muscles relax (Note: External and internal intercostal muscles are antagonistic, when one contracts, the other relaxes.)

Name: __________________ Topic: Respiration in humans Concepts Summary Notes Nan Hua High School Biology 4 LO: D escribe the effect of tobacco smoke and its major toxic compon ents – nicotine, tar and carbon monoxide, on health Chemical Properties of the chemicals Effects on the body Nicotine ● Addictive ● Causes release of adrenaline ● Causes blood to clot easily ● Increase in heartbeat and blood pressure ● Increased risk of blood clots in blood vessels Carbon monoxide ● Binds with haemoglobin to form carboxyhaemoglobin which reduces the oxygen carrying capacity of red blood cells, reducing the amount of oxygen being transported around the body. ● Increases the rate of fatty deposits on inner arterial wall ● Damages lining of blood vessels ● Death if concentration in air is increased by 1% ● Increased risk of atherosclerosis ● Increased risk of blood clotting in arteries

Name: __________________ Topic: Respiration in humans Concepts Summary Notes Nan Hua High School Biology 5 Tar ● Carcinogenic (cancer causing) chemical which induce uncontrolled cell division of the epithelium ● Paralyses cilia lining the air passages ● Blockage in the air sacs and reduction in gas exchange efficiency ● Dust particles trapped in the mucus lining the airways cannot be removed LO: Define and state the equation, in words and symbols, for aerobic respiration in humans Definition: Aerobic respiration is the oxidation of glucose in the presence of oxygen with the release of a large amount of energy. Carbon dioxide and water are released as waste products. Word equation: Glucose + Oxygen → Carbon dioxide + Water + Large amount of energy Chemical equation: C6H12O6 + 6O2 → 6CO2 + 6H2O + Large amount of energy LO: D efine and state the equation, in words only, for anaerobic respiration in humans Definition: Anaerobic respiration is the oxidation of glucose in the absence of oxygen. Anaerobic respiration releases lesser energy than aerobic respiration and produces lactic acid. Word equation: Glucose → Lactic acid + Small amount of energy Compare aerobic respiration and anaerobic respiration: Similarities: Both aerobic and anaerobic respiration release energy for cellular activities. Both aerobic and anaerobic respiration involves breakdown /oxidation of glucose/ use glucose as a substrate.

Name: __________________ Topic: Respiration in humans Concepts Summary Notes Nan Hua High School Biology 6 Differences: Aerobic Respiration Anaerobic Respiration requires oxygen to be present does not require oxygen to be present releases large amount of energy releases small amount of energy breaks down glucose to water and carbon dioxide breaks down glucose to lactic acid in humans / ethanol and carbon dioxide in plants occurs in the mitochondria occurs in the cytoplasm LO: Describe the effect of lactic acid in muscles during exercise • Exercise increases muscular contractions. • Energy demand increases. • Rate of respiration increases to meet increased in energy demand. • Heart rate increases to increase blood supply which contains oxygen and glucose to the muscles. • If the increased oxygen intake is not able to meet the oxygen demand, an oxygen debt results and anaerobic respiration takes place to release the energy required. • Lactic acid builds up slowly in muscles during exercise. • At high enough concentrations, lactic acid will cause fatigue and muscular pain. The body needs to rest and recover. • An oxygen debt is the volume of oxygen required to remove the lactic acid that has been built up. • Breathing rate continues to be high and starts to decrease after exercise to repay the oxygen debt and lactic acid is removed from the muscles and transported to the liver. • In the liver, the lactic acid is oxidised to release energy, which is used to convert the remaining lactic acid to glucose, which is transported back to the muscl