8C - Breathing and Respiration (Studysheet) (1).pdf

Name : _____________________ Date : ____ / ____ / 2024 Biology - Summary Sheet 8C – Breathing and Respiration Subject : Biology Class : 8th Grade ( ) 8Ca Aerobic Respir...

Name : _____________________ Date : ____ / ____ / 2024 Biology - Summary Sheet 8C – Breathing and Respiration Subject : Biology Class : 8th Grade ( ) 8Ca Aerobic Respiration + 8Ce Anaerobic Respiration Sats how much oxygen is in the body A device called an oximetry is used to measure the saturation (sats) of oxygen, which is shown as a percentage on the oximetry. Percentage Meaning / Status of patient 100 % Blood is fully saturated and carries as much oxygen as it can. 95 – 100 % Percentage sats of most people. It means that the blood is perfectly saturated. Below 80 % Blood is not well saturated and is not carrying a sufficient amount of oxygen. Organs may be damaged. Respiration & Breathing Note Some students think that the terms respiration and breathing are the same. In fact, there is a huge difference between them. Respiration : The breaking down of glucose in the presence of oxygen, to produce water and carbon dioxide (by the help of energy from food). Breathing / Ventilation : The movement of the chest as a result of inhalation (breathing in / taking in air) and exhalation (breathing out / giving out air) 1 Page Respiration There are two types of respiration, which differ according to whether oxygen is involved in the process or not. Aerobic respiration is where we use oxygen is present in order for a combustion reaction of glucose (C6H12O6) to occur. Anaerobic respiration doesn’t involve oxygen. During anaerobic respiration, glucose is broken down into lactic acid. The processes that occur in aerobic and anaerobic respiration can be summarized using a word equation: Aerobic Respiration : oxygen + glucose → carbon dioxide + water (+ATP) Anaerobic Respiration : Glucose → lactic acid (+ some ATP) Comparing the types of Respiration There are some similarities and some differences between aerobic and anaerobic respiration. These are summarized in tables 3 & 4 below. Aerobic Respiration Anaerobic Respiration Both have glucose as the reactant Both release energy Both are used during strenuous exercise Table 3 – Similarities between aerobic and anaerobic respiration. Aerobic Respiration Anaerobic Respiration Produces water and carbon dioxide Produces lactic acid Does not tire the muscles Makes muscles become tired quickly Occurs in the mitochondria of all living Occurs in the cytoplasm of muscle cells cells Releases more energy than anaerobic Releases less energy than aerobic respiration respiration Forms more ATP than anaerobic Forms less ATP than aerobic respiration. respiration. Table 4 – Differences between aerobic and anaerobic respiration. 2 Page  8Cb Gas Exchange System Ventilation and Breathing When you exercise, your breathing rate (breaths per minute) and your pulse rate Explain (beats per minute) increase. Why This is because your cells need more oxygen and glucose for respiration. Breathing is the movement of muscles in the diaphragm and attached to the ribs as a result of inhalation and exhalation. Breathing ventilates the lungs. Ventilation is the movement of air into and out of the lungs. Question: What do muscles in the diaphragm do during breathing ? 3 __________________________________________________________________ Page  Keeping the airways clean Our lungs need to be clean. Some cells (called goblet cells) are in the tubes of our lungs, which produce a sticky liquid called mucus. Mucus traps dirt, dust and microorganisms; which might be a pathogen and this might save us from getting a disease. Other cells called ciliated epithetical cells, have hair like structures called cilia, which swap (waft) the mucus out of the lungs into the mouth, where they can be either swallowed into the oesophagus or spat out. Mucus is produced by goblet cells and wafted by cilia in cilliated epithelial cells. Question 2 : Chemicals in cigarette smoke damage the ciliated epithetical cells. What would happen to a smoker if his ciliated epithelial cells where damaged by the chemicals in cigarette smoke ? Less mucus is waftred out of the body by cilia so there will be more mucus in the lungs __________________________________________________________________ whichi si dangerous and in severe cases it may lead to death. __________________________________________________________________ Looking Ahead (Extension of Work) Even if you swallow the mucus that has pathogens, you will not be infected even though they entered your body. That is because the hydrochloric acid in the stomach will kill the pathogens in the mucus 4 Page before they enter your body. Gas Exchange The gas exchange is the “exchanging” of gases: taking in oxygen and giving out carbon dioxide. Gas exchange occurs by diffusion. There is an overall movement of particles from a place where they are concentrated to where they are at lower concentration.down the concentration gradient Different organisms use different organs for gas exchange (swapping one gas for another). For example, gills in fish, lungs in humans and stomata in plants. Adaptations of the Lungs The lungs have adaptations for gas exchange to occur more efficiently: 1. Has about 700 million little pockets called alveoli. This gives the lungs a large surface area. 2. The alveoli have walls that are one cell thick. 3. Blood capillaries around each alveolus have thin walls as well. Question 3 : In order, list the organs through which air passes when we exhale air. __________________________________________________________________ Question 4 : State whether the following statement is true or false. 5 Breathing is a term that has the same meaning as ventilation. ( ) Page  8Cc Getting Oxygen In the Blood After gas exchange, where oxygen diffuses into the blood through blood capillaries and carbon dioxide out of them, oxygen sticks to the molecules of hemoglobin in the red blood cells. This changes the colour of the cell from dark-browny red to bright red. Figure A on page 44 of the coursebook shows the two different types of blood. Figure 4 shows the difference between a cell with oxygen (oxygenated cell) and a cell without oxygen but with carbon dioxide (deoxygenated cell). From the lungs, blood is carried to the heart through capillaries then veins. Afterwards, they enter the heart and are transported to the rest of the body through arteries which then subdivide into capillaries. Breathing Rate and Exercise When you exercise, you need to supply your muscles with more oxygen so that more aerobic respiration can occur to release enough energy for them to move rapidly. More glucose will be transported to the muscle cells also for more aerobic respiration. So, your breathing rate increases so that more oxygen can dissolve in the blood plasma and your heartbeat rate will increase to transport the oxygenated blood to the muscle cells for aerobic respiration. Question 5 : How is glucose carried to the cells ? 6 Page __________________________________________________________________ Question 6 : a. Explain why a boy’s breathing rate doubles during a swimming race. __________________________________________________________________ __________________________________________________________________ b. Explain why his pulse rate also changes during his race. __________________________________________________________________ __________________________________________________________________ Smoking An inefficient transportation of oxygen can occur due to several reasons, which include: Narrowed blood vessels Poisons Poor gas exchange in the lungs, due to problems that reduced the surface area of the lungs When temperatures are cold and in order to avoid heat loss, our blood vessels become narrower and less blood reaches the cells as it is harder for the cells to move through the vessels when they are narrow. If this causes cells to die, it results in frostbite. Cardiovascular Diseases Blood vessels become narrower due to a fatty substance collecting inside them. If the blood flow decreases, then cells start to die. This fatty substance builds up in smokers more than people who are non-smokers. Heart diseases is a type of cardiovascular disease in which the blood supply to the heart muscle is reduced so it dies. When the heart muscle cell dies, this causes a heart attack. Carbon Monoxide Some appliances and vehicles emit carbon monoxide, which is a poisonous gas that sticks to hemoglobin in red blood cells instead of oxygen; transporting less oxygen 7 Page around the body. The person become breathless and tired. Cigarettes The chemicals in cigarette smoke are harmful. Cigarette smoke can also trigger asthma, in which the tiny tubes in the lungs become narrow and start filling with mucus. Less air can get into and out of the lungs, causing shortness of breath. Question 7 : Choose the correct answer in the following. Question 8 : The diagram shows the location of the lungs in a horse. 8 Page a. Complete the missing blank in the following statement. The part labelled X is the ____________________________. b. Which row of the table describes what happens when the horse inhales ? c. The table shows the percentage of the total blood flow in different parts of the horse at rest and when running. Comment on the changes in the percentage of the total blood flow in these parts of the horse’s body. When running the horse will use his leg muscle so it would require more oxygen to move __________________________________________________________________ but when it is at rest the horse won't use it's leg muscle thus making it have a less blood flow __________________________________________________________________ When resting better absorption occurs so the intestine would need more blood flow and oxygen __________________________________________________________________ but when running there will be far less absorption so the horse would need far less blood flow __________________________________________________________________ oxygen to the intestine thus making it use less when running than resting. __________________________________________________________________ d. Draw a flow chart to show the organs that air will pass through when the horse exhales. 9 Page  8Cd Comparing Gas Exchange Elephant Seals Marine animals such as elephant seals need to spend long periods underwater. These animals have adaptations that allow them to spend long times underwater without breathing. As an example, elephant seals can stay 2 hours underwater without breathing because they have an organ called the spleen that stores blood full of oxygen which is pumped when needed. The above table shows the percentages of gases in inhaled air and exhaled air. How can we prove that respiration has occurred ? 1. Test for the presence of carbon dioxide, as it is a product of respiration. To test for the presence of carbon dioxide using a method from the table below. Name of solution / reagent Original colour Change in color in case used of a positive result Limewater (solution of sodium Clear and colorless Turns from clear to 1 hydroxide) milky / cloudy 2 Hydrogen carbonate indicator Pink Turns from pink to yellow 3 Measuring pH A universal indicator changes color from green to red, yellow, or orange based on the solution acidity, which is determined by the amount of dissolved carbon dioxide in the water. 10 2. Look for a rise in temperature, because some of the energy released by a cell during respiration is as heat, which increases the temperature of the exhaled air. Page Gas exchange systems of animals and plants Fish and Gills Mammals can use lungs to get oxygen and so must breathe air. However, some animals never breathe air because they can extract dissolved oxygen in water, often using gills. gas exchange in fish Plants and Stomata For photosynthesis, plants need carbon dioxide to make glucose. + oxygen Plant cells then release energy from the glucose using aerobic respiration, which happens in all cells, all the time. To allow gases in and out, land plants have many tiny holes in the leaves called stomata. 11 Page