Topic 2 Organisms and Energy 1.Aerobic Respiration 2.Exercise 3.Anaerobic Respiration 4.Photosynthesis 5.Limiting factors 6.Water Transport

Recall that respiration is a process used by all living organisms that releases the energy in organic molecules Explain how the human circulatory system facilitates respiration,including: a) glucose and oxygen diffuses from capillaries into respiring cells b) carbon dioxide diffuses from respiring cells into capillaries Define diffusion as the movement of particles from an area of high concentration to an area of lower concentration Demonstrate an understanding of how aerobic respiration uses oxygen to release energy from glucose and how this process can be modelled using the word equation for aerobic respiration

Aerobic Respiration Learning Objective: Explain what respiration is with a description of bodily processes that support the process. Learning Outcomes C: Define aerobic respiration and state the word equation B: Explain why respiration is important in living organisms. A: Model and explain the role of diffusion in supporting respiration.

Starter What is Respiration? How is it different from breathing?

Structures of the respiratory system

Lets First look at how we breath Air is breathed in through the nose and mouth, and through the ________ The trachea divides into the two __________ which branch out into narrower tubes called ____________. The bronchioles end in tiny air sacs called ____________ that have very thin walls, which makes the exchange of gas easier.

The Respiratory System Trachea Bronchi BronchiolesAlveoli Air is breathed in through the nose and mouth, and through the TRACHEA. The trachea divides into the two BRONCHI, which branch out into narrower tubes called BRONCHIOLES. The bronchioles end in tiny air sacs called ALVEOLI, that have very thin walls, which makes the exchange of gas easier.

The Respiratory System TASK: Use these words to label Alveoli Bronchi Bronchioles Trachea stopwatch.com/eggtimer- countdown/full-screen/

TASK: Breathing Task Worksheet You have 2 Minutes to put the statements in order ! stopwatch.com/eggtimer- countdown/full-screen/

Waste products of aerobic respiration Breathing in obtains the oxygen needed for aerobic respiration. How does the body get rid of the waste products? Breathing out removes the waste products of aerobic respiration. How can the waste products of this reaction be identified? Aerobic respiration releases energy that is useful. This process is a chemical reaction between glucose and oxygen which also generates waste products. ? glucose oxygen ? energy

Aerobic respiration: summary Summarize the process of aerobic respiration in a sentence. Aerobic respiration is a chemical reaction so it can also be summarized in a word equation. What is the word equation for this vital chemical reaction? Aerobic respiration is a chemical reaction that takes place in all living cells, in which glucose reacts with oxygen to produce carbon dioxide and water and stored chemical energy is released.

Aerobic respiration Aerobic – needs oxygen!! Word equation for aerobic respiration: ++ +

carbon dioxide glucose oxygen water carbon dioxide water oxygen glucose energy

What is diffusion? Dissolved substances have to pass through the partially permeable cell membrane to get into or out of a cell. Diffusion is one of the processes that allows this to happen.. What substances are we talking about?

How does smell travel to our nose? In this example a sock is 2 metres away from the person. 1.Where is the smell strongest? 2.How does the smell travel from the sock to the person?

Breathing involves the exchange of gases in the lungs, a process which occurs by diffusion. What is the vital gas that you breathe in? Diffusion and breathing The lungs have a huge surface area to maximize the exchange of oxygen and carbon dioxide with each breath. Where in the lungs does gas exchange take place? oxygen carbon dioxide What is the waste gas that you breathe out?

Diffusion in action: one gas

Diffusion in action: two gases

Changing concentrations The rate of diffusion depends on several factors, such as the distance the particles have to travel and the difference in concentration. Molecules diffuse until they are evenly spaced apart and equilibrium is reached. During diffusion molecules move from an area of high concentration to an area of low concentration. They are said to move down a concentration gradient. Diffusion is a passive process which means that no energy is needed. high concentration low concentration

What happens in the alveoli?

How are alveoli adapted? Alveoli have several adaptations that help to make gas exchange very efficient: They are very thin – only one cell thick. They are covered by a network of fine capillaries, enabling gases to pass almost directly between the lungs and bloodstream. They are moist, encouraging gas molecules to easily dissolve. They have a large combined surface area, allowing large amounts of gases to be exchanged with each breath.

Cross-section through an alveolus deoxygenated blood (from body tissues) oxygenated blood (to body tissues) air in/out Alveoli are the tiny air sacs at the end of the bronchioles, in which gas exchange occurs. alveolus capillary red blood cell

Gas exchange animation

Inhaling increases the concentration of oxygen molecules in an alveolus. At this point, how does this compare with the concentration of oxygen in deoxygenated blood in the capillary? Diffusion and breathing – oxygen deoxygenated blood from the body oxygenated blood to the body When you inhale, the concentration of oxygen inside each alveolus is higher than in deoxygenated blood. oxygen into alveoli

How is the concentration of oxygen in the blood increased? Oxygen molecules diffuse across the lining of the alveolus into the blood in the capillary, moving from higher to lower concentration. Diffusion and breathing – oxygen oxygenated blood to the body deoxygenated blood from the body oxygen into alveoli diffusion When you inhale, the concentration of oxygen inside each alveolus is higher than in deoxygenated blood.

Deoxygenated blood from the body is low in oxygen but has high levels of carbon dioxide. How does this compare with concentration of carbon dioxide in the alveolus? Diffusion and breathing – carbon dioxide deoxygenated blood from the body oxygenated blood to the body The concentration of carbon dioxide in deoxygenated blood is higher than in the alveolus.

How is the concentration of carbon dioxide in the blood reduced? Carbon dioxide molecules diffuse from the blood in the capillary into the alveolus, moving from higher to lower concentration. Diffusion and breathing – carbon dioxide deoxygenated blood from the body oxygenated blood to the body The concentration of carbon dioxide in deoxygenated blood is higher than in deoxygenated blood. carbon dioxide out of alveoli diffusion

Gas Exchange es/revise5.shtml es/revise5.shtml TASK: Colour in diagram, red or blue Red = Oxygen Blue = Carbon Dioxide

Aerobic respiration is a chemical reaction shown by the equation: ________ + oxygen → carbon dioxide + ________ (+ energy) Aerobic means needing __________. __________ comes from carbohydrates in food. It is carried to the cells of the body in the bloodstream. Oxygen is absorbed by the blood in the lungs and travels to the __________ of the body. Both substances enter a cell by a process called __________. Carbon dioxide leaves the cells and travels in the blood to the __________, where it is lost from the body. Respiration provides the cells with __________, which can be used for other things such as __________ of muscles, and sending messages through nerves. energy cells glucose contraction diffusion oxygen water lungs glucose

Diffusion: true or false?