Respiration Noadswood Science, 2016

Sunday, May 20, 2018 Respiration To know what respiration is

Precise Learning Students should be able to describe cellular respiration as an exothermic reaction which is continuously occurring in living cells. The energy transferred supplies all the energy needed for living processes. Respiration in cells can take place aerobically (using oxygen) or anaerobically (without oxygen), to transfer energy. Organisms need energy for: chemical reactions to build larger molecules movement keeping warm

Respiration What do you know about respiration? What is needed to live? Do all organisms require the same thing? In pairs, discuss any facts you know in the next two minutes

Respiration “Respiration is breathing in and out” “Plants photosynthesise but animals respire” “During respiration, oxygen is produced” “During respiration, energy is produced” Although these comments may sound correct, every single one is wrong!!!

Respiration Respiration is not the same thing as breathing (ventilation) Respiration is a chemical process in which energy is released from food substances, such as glucose (sugar) Aerobic respiration needs oxygen to work – most of the chemical reactions involved in the process happen in specialised cell organelles – the mitochondria

Respiration Respiration takes place in the cells (it is not “breathing in and out”) Respiration is the release of energy (from glucose) in our cells Animals and plants respire

Respiration Equation Aerobic Respiration: - glucose + oxygen  carbon dioxide + water + (energy) C6H12O6 + 6O2  6CO2 + 6H2O + (energy)

Aerobic Equation

Respiration Use Respiration is used by both animals and plants… The energy released is used to: - Build up smaller molecules into larger ones, as well as: - Enabling muscles to contract To build up tissue Maintaining a constant body temperature In plants to build up sugars, nitrates and other nutrients To build up amino acids (and eventually proteins)

Testing How could you test for respiration? What could you measure to prove it was taking place and at what rate? During respiration the gas carbon dioxide is produced - testing for this would show if respiration occurred, and at what rate The test for carbon dioxide is to use limewater (it goes cloudy) Water is also produced - we could measure this (how much we exhale) Energy is also released during respiration = which is used by our cells (however it is difficult to test this, but you could monitor the activity of the organism (the heat released))

Hand Squeeze Use the hand squeezers and squeeze every second for as long as you can – record the time you continued for Group collect the results to see who fatigues quickest and who can sustain the longest… Record your results and graph…

Key Words Have a go at the following wordsearch: - Words to find: - Aerobic Anaerobic Carbohydrase Carbohydrate Carbon dioxide Energy Glucose Lactic acid Oxygen Respiration Water

Test

Test

Practice Questions What is the equation for aerobic respiration? Give three ways animals use energy for respiration

Glucose + Oxygen  Carbon Dioxide + Water + Energy Answers What is the equation for aerobic respiration Glucose + Oxygen  Carbon Dioxide + Water + Energy Give three ways animals use energy for respiration – building larger molecules from smaller ones / contracting muscles / keeping warm etc…