Respiration

Learning Intentions I can give examples of why energy is needed by organisms and cells I can state that respiration is the process that releases energy in cells I can give the word equation for aerobic respiration I can describe what a respirometer is used for and the purpose of each of it’s parts

Success Criteria I can carry out several experiments related to respiration I can set up a simple respirometer and understand how to gain results from a respirometer experiment I can carry out an experiment to investigate the volume of carbon dioxide produced when I breathe out

Energy Energy cannot be created. Energy cannot be destroyed. 18 September, 2018 Energy Energy cannot be created. Energy cannot be destroyed. Energy exists in a number of different forms, e.g. heat, light, sound, electrical, etc… G Davidson

Chemical Energy This is stored energy. 18 September, 2018 Chemical Energy This is stored energy. When one chemical substance is changed into another during a chemical reaction, this stored energy is often released. It may be released as heat, light, sound, etc.. G Davidson

18 September, 2018 Chemical Energy Not all the energy released by the sun arrives in the cells. Each time an energy conversion takes place some energy is “lost”. This lost energy is not destroyed – it simply passes out of the pathway in another form and is therefore, wasted energy. G Davidson

Energy Changes in Organisms 18 September, 2018 Energy Changes in Organisms This energy can be converted into a variety of forms. Organisms consist of vast numbers of different kinds of cells. All cells need energy. Each cell or group of cells has a particular function to carry out. Individual cells are capable of carrying out several different energy conversions. G Davidson

Respiration  Respiration is the process which takes place in all living cells to release chemical energy all the time. The concept that it can occur with or without oxygen should also be considered. GLUCOSE + OXYGEN ENERGY + CO2 + WATER

18 September, 2018 Respiration Carbohydrate in the form of glucose is transported to each cell in an organism. The process by which cells release the energy stored in glucose molecules is called CELLULAR RESPIRATION. There are 2 types: Aerobic respiration – this occurs when there is a plentiful supply of oxygen to the cell. Anaerobic respiration – this occurs when there is no oxygen available to the cell. G Davidson

18 September, 2018 Energy Release Warm blooded animals maintain their body temperature above that of their surroundings. This means the animal is losing its heat to its surroundings. This heat energy must be coming from energy locked up in food. The heat energy is released as part of respiration. Plants also give off heat because they are respiring also. G Davidson

An important point about respiration Look at the respiration experiments in the classroom and use the question sheets to write some notes on these. Live vs dead germinating peas for oxygen uptake Plant in bell jar to show carbon dioxide release Germinating peas in flasks to show heat energy given off An important point about respiration Heat energy produced by respiration is important in the metabolism of cells, because it increases the rate of chemical reactions  

18 September, 2018 Oxygen Uptake It is possible to measure changes in oxygen content using a RESPIROMETER. Each type of respirometer contains a chemical to absorb and therefore remove carbon dioxide given out by the organism. The respirometer measures both the volume of oxygen taken up by a respiring organism, and the volume of CO2 released. They are equal. GLUCOSE + OXYGEN ENERGY + CO2 + WATER G Davidson

18 September, 2018 G Davidson

Respirometers Set up a simple respirometer

Anaerobic respiration

Learning Intentions I can describe the process on anaerobic respiration in both plants and animals

Success Criteria I can write the word equation for anaerobic respiration in both plants and animals I can carry out an experiment to demonstrate anaerobic respiration in muscle cells

Anaerobic respiration This type of respiration occurs when there is no oxygen available to the cell.

Animals Glucose  Lactic acid When lactic acid build up in animal tissues this causes muscle fatigue and is only removed when oxygen level increase

Plants Glucose Ethanol + Carbon dioxide This process is also know as fermentation and is used by many industries

Respiration rate

Factors affecting respiration rate Brainstorm what do you think will affect how quickly respiration occurs within cells

Learning intentions I can state factors that may affect the rate of aerobic respiration in yeast to include some of the following: temperature, oxygen concentration type of yeast concentration of yeast concentration of glucose/sucrose

Success Criteria I can carry out an investigation into the rate of aerobic respiration in yeast.

Yeast at Work Yeast makes many useful products. 18 September 2018 Yeast at Work Yeast makes many useful products. E.g. yeast can break down glucose into carbon dioxide and ethanol (alcohol). This is called fermentation. Yeast obtains energy by doing this. G Davidson

18 September 2018 Yeast Cells G Davidson

Investigation into respiration rates in yeast Collect a boiling tube and fill with bicarbonate indicator Half fill a pipette with yeast and sugar suspension Use metal washer to weigh down the pipette. Place pipette in boiling tube tip upwards Start timer and count the number of bubbles produced in one minute (You may need to alter the time allocated for counting) Record your results Repeat the experiment altering only the factor you decided to change When you have completed your investigation draw a graph of your results Write a conclusion and evaluation for your experiment