Computer Interface Cobra4

Transpiration of leaves

Principle

To prepare and analyse diagrams to illustrate the transpiration of plants, depending on different environmental conditions, using a wireless data acquisition system:

Photosynthesis (O2 pressure measurement) (with Cobra4)

Principle

Representation of the photosynthesis rate of a plant by measuring the oxygen pressure increase, in
white and green light as well as in the dark.

Glycolysis (temperature measurement)

Principle

Investigating the temperature increase during the fermentation of sugar by yeast cells.

The enzymatic activity of catalase

Principle

To examine the enzymatic decompositionof hydrogen peroxide, a cell respiratorypoison, in the liver.

Photosynthesis (bubble-counting-method)

Principle

Measurement of the photosynthesis rate as a function of light intensity by counting the oxygen bubbles
that are released by a water plant.

Glycolysis (pressure measurement)

Principle

The aim of this experiment is to prove glycolysis by means of measuring the CO2 production under various
experimental conditions (temperature, pH).

Ionic permeability of the cell membrane

Principle

The cell membrane controls the transport of nutrients and water into the cell as well as the transport of waste products and water out of the cell. This can be passive, i.e. caused by osmotic processes, as well as active. The aim of this experiment is ...

Determination of the Michaelis constant

Principle

The enzymatic hydrolysis of urea in an aquous solution yields carbon dioxide and ammonia. The ions of
these compounds increase the conductivity of the solution. The speed of urea hydrolysis, which is
caused by the urease enzyme, can be de ...

Substrate inhibition of enzymes

Principle

The enzymatic hydrolysis of urea in aqueous solution liberates carbondioxide and ammonia. The ions of these compounds increase the conductivity of the solution. Conductivity measurements can therefore be used to measure the rate of hydrolysis of urea ...

Enzyme inhibition (poisoning of enzymes)

Principle

The enzymatic hydrolysis of urea in aqueous solution liberates carbon dioxide and ammonia. The ions of these compounds increase the conductivity of the solution. Conductivity measurements enable the rate of hydrolysis of urea by the enzyme urease to b ...

Electrolysis

Principle

The characteristic curve of current against voltage of an electrolytic bath containing copper sulphate solution and having copper electrodes is measured. Visible changes in the electrodes and the bath are observed.

Tasks

Floating and sinking

Principle

The buoyancy force equals the weight of the displaced liquid: This experiment uses Archimedes' principle to determine to which extent the buoyancy depends on the mass and volume of a body and the density of the liquid.

Cooling by evacuation

Principle

When the air pressure above a watersurface is reduced, the water begins to boil at a certain temperature. The temperature of the water is hereby reduced and further evacuation can finally bring it to 0°C and even lower.

We examine our drinking water

Principle

This experiment shows how much the quality of drinking water of various locations in the same region can vary. The comparison of tap water with bottled mineral water and distilled water leads to surprising results.

Altitude measurement on a trail

Principle

The altitude profile of a hiking trail or route to school can be measured during a school trip or as an exercise for the students. The altitude profile can also be used to demonstrate that the atmospheric pressure decreases when the altitude increases ...