Respiration Photos from wikimedia commons Biodiversity and interdependence

Respiration Photos from wikimedia commons

Biodiversity and interdependence I can contribute to the design of an investigation to show the effects of different factors on the rate of aerobic respiration and explain my findings. SCN 4 -02 b

Glucose + oxygen carbon dioxide + water+ energy Factors affecting rate of respiration • • Temperature Oxygen level Supply of glucose Demand for ATP- e. g. increased exercise etc. Measuring rate of respiration Directly • Oxygen consumption with time • Carbon dioxide evolution with time Indirectly • Breathing rate • Pulse rate/ heart rate

Ideas? Image from yeastgenomics. ca/about Images from wikimedia commons

Using live animals Pictures from wikimedia commons www. sserc. org. uk

Classic experiments- Standard grade and Higher Biology Pictures from Torrance, Standard grade and Higher Still Biology.

Investigating the effect of temperature on the rate of respiration

Simple respirometer

Simple respirometer construction

Mark glass before bending

Bent glass tube Threading tube through stopper

Threading tube through stopper

Simple respirometer

On ice 4 o. C, room temp and 35 o. C

Setting up your experiment • To set up each respirometer, place three spatulas of soda lime pellets into each boiling tube. • Using a spoon or the plastic forceps (or fingers!) put twenty maggots into the plastic centrifuge tube. Cover the end with muslin and hold in place with an elastic band. • Place the plastic tube inside the boiling tube and place them at the required temperature – into the test tube rack in the water bath, or using the clamp stand for room temp and on ice. • Leave for ten minutes to acclimatise.

• Seal the tube with the respirometer, making sure you have a tight fit with the rubber bung. • Blot the end of the respirometer tube onto a paper towel to remove any liquid. • To run the experiment, place the end of the respirometer into the small bottle of food colouring. The liquid will rise into the tube. When you are ready to start, mark the level of the liquid with the pen and start the stopwatch. • Run the experiment for ten minutes, then mark the final level of the liquid. Measure the distance the liquid has risen in mm to get your results.

• Observe the maggots behaviour and activity levels and record your observations. • Record your results and put them on the board at the side so we can collate the group results. Remember to wash your hands thoroughly with hot water and soap at the end.