DrDAQ

Data logger, oscilloscope, signal generator and more!

DrDAQ is a versatile instrument that connects to the USB port of any PC. Using the supplied PicoScope software it can be used as an oscilloscope, spectrum analyzer and signal generator.

From just £89.00

More

Respiration of Peas

IntroductionEducational data loggerKeyStage 3 - 5

Aerobic respiration is the process in which glucose and oxygen, through the action of enzymes in mitochondria, produce carbon dioxide, water and lots of energy. In this experiment the use of oxygen in the aerobic respiration of peas can be seen in that, in a sealed container, the level of oxygen reduces with time.

Equipment required

  • PC with PicoLog datalogging software installed
  • DrDAQ data logger
  • Oxygen in air sensor
  • 2 litre beaker
  • 100 ml  beaker
  • Beehive shelf
  • Trough — ice–cream container
  • Water
  • Peas — soaked overnight in water with a little thymol to kill off bacteria
  • Tissue handkerchief or cotton wool

Experiment set up

  1. Connect the DrDAQ datalogger to the parallel port (or USB if you are using a USB to Parallel port adaptor.)
  2. Mount the oxygen sensor pointing upwards on the beehive shelf. A little BluTack is useful for anchoring it in place securely. Run it's connecting lead through the central hole of the beehive shelf.
  3. Fill the trough with water at room temperature to a depth of about 3 cm and place the beehive shelf with the sensor into it. Plug the sensor’s connecting lead into External socket 1 on DrDAQ.
  4. Place a tissue handkerchief or piece of cotton wool into thebottom of the 100 ml  beaker and place 10 or so peas onto it. Place this beaker in the water alongside the beehive shelf. You may find it useful to anchor it down with BluTack.
  5. Now place the 2 litre beaker, upsidedown, over the beehive shelf and 100 ml  beaker and into the water so that it seals in the air.
Respiration experiment equipment setup

Figure 1: the equipment set up

A centrally heated and thermostatically controlled room or laboratory should not change much in temperature, probably only of the order of 2–3 °C, assuming that windows are not suddenly opened or lots of bunsen burners lit.

Carrying out the experiment

  1. Load PicoLog and configure it to collect readings of the oxygen sensor every minute for three days (4320 samples.) This will not in fact be the data set that you will wish to retain - it is to enable you to know when it is useful to start recording for real.
  2. Set it to start recording. Refer to the oxygen level regularly over the next two to three days. During that time the peas should start to germinate and respiration will begin, shown by a fall in oxygen level. At this stage stop the recording and discard the data.
  3. Reconfigure PicoLog to collect readings of the oxygen sensor every minute for two days (2880.) Set it to start recording. When datalogging is compete, display the graph of % oxygen against time.

Ideally one would also investigate how the temperature of the peas and their environment changed as respiration took place — it should rise. However, it is difficult to design a situation in which this can be easily achieved whilst providing a sealed atmosphere environment. Probably the best that could be done would be to place the peas, oxygen and temperature sensors inside an upturned vacuum flask over water. The external temperature would beed to be monitored too. Obviously some energy will be transferred through the water seal, but a rise in temperature of the peas and their environment over the external surroundings should be noticeable.

Further study

An extension to the basic experiment could be to place the trough, beehive shelf, beakers, peas,etc into a thermostatically controlled heated water-bath, or on a hot-pate, and see if temperature affects the rate of respiration and so the speed of uptake of oxygen. Temperature up to around 40°C are OK.

A further investigation could be to see if light intensity has any effect, illuminating the peas with a light bulb and additionally recording the light level. One of the energy–saving fluorescent bulbs should be used so that little direct heating is caused. Readings should then be collected from the oxygen sensor connected to DrDAQ externally and from DrDAQ’s on-board light level sensor placed alongside.

Testimonials

  • I have been using my 4224 PicoScope for years. I travel abroad so this has been ideal due to its physical size. Storage of waveforms on my Laptop is very easy allowing me to quickly email waveforms to my Colleagues.

    Andrew
  • Not many USB scopes works on Win & Mac & Linux too, so that proves me that guys from Pico really cares about us, customers. This made my decision much easier when I was looking to buy an USB scope.

    Raul Trifan
  • We have been using Picoscope 6404D for quite some time, and are amazed by its accuracy and powerful emulations while working with numerous signal evaluations.

    J Mohanty
  • PicoLog TC-08: This is a very nice unit that works consistently and reliably.

    Jeff Hulett
  • It is a great scope. I had a weird problem - it did not work on one of my PC’s. Customer service gave me first class service. If I could give 6 stars for customer service - I would do so.

    Niels Larsen
  • Perfect Partner for Development of Encoder controlled Stepper Motor Actuators. Since the included software is really stable, this type of device is a great tool for great tasks!

    Helmut Schoettner
  • A superb piece of equipment worth its weight in gold

    Nigel Clinch
  • So simple to use & beats any other I have ever used hands down.

    John D Samsing
  • Great functionality in a compact size. I really like moving the mouse pointer to a position and having the Time and Voltage display the values at that point. Calibration equipment is a breeze with that feature.

    Don Horein

PC oscilloscope and data logger products

Tel: +1 800 591 2796 (Toll Free)