Biophysics Laboratory | Faculty of Applied Physics and Mathematics at the Gdańsk University of Technology

Biophysics Laboratory

Location: Main Building Laboratory rooms 23&28

Person in charge: dr Brygida Mielewska, Gdańsk Tech professor

Contact: Main Building room 114, phone +48 58 347 28 86, e-mail: brymiele@pg.edu.pl

The aim of the laboratory is to familiarize students with:

• description of physical phenomena occurring in biological systems,
• observation of the impact of various physical factors on the living organism,
• development of the ability to use measuring instruments,
• analysis of the experimental data  and assessment of measurement uncertainties,
• basic methods of accounting for uncertainty of complex quantities.

The exercises enable students to study typical phenomena occurring in biological systems (e.g. osmosis or diffusion potential), as well as to study the characteristics of human organs using models (e.g. exercise: "Acoustic spatial orientation") or their own organisms (e.g. exercises: "Determining the field of vision of man", "The resolution of the human eye").

Exercise list

1. Acoustic spatial orientation
2. Determination of the field of vision of the human eye
3. Human eye spatial resolution
4. Determination of the diffusion potential
5. Determination of the audibility threshold curve and the frequency discrimination threshold Neurosimulator – study of nerve cell excitation
6. Refractometry – measurement of the relationship between the solution concentration and the refractive index

Exercise 1. Acoustic spatial orientation.

Objectives of the exercise:

1. To familiarize students with the problem of sound wave propagation and the reception of sound wave by the human ear, in particular the role of the external ear in receiving and amplification of sound, and to familiarize students with the issue of the location of sound sources in space, formation of an inter-ear time difference and the inter-ear difference of the sound intensity
2. Measurement of the inter-ear time difference and the inter-ear intensity difference depending on the angle of the incidence using the human head model
3. Determination of angular resolution of the system
4. Analysis of collected data and formulation of conclusions

1. Measurement module Cobra3 (connected to 12V power supply and computer)
2. Head model
3. Rotating mount
4. Angle scale
5. Tuning fork (440Hz) with resonant box
6. Rubber hammer

Exercise 2. Determination of the field of vision of the human eye

The objectives of the exercise:

1. To familiarize students with the issue of light wave reception by the human eye, the role of rods and cones in photopic and skotopic vision, and the problem of visual dysfunctions
2. Determination of the human field of vision for the left and right eye, for white, red, blue and green light using a perimeter
3. Determination of the position of the blind spot
4. Study of the field of vision field of binocular vision
5. Analysis of the collected data and formulation of conclusions

1. Perimeter
2. Angular scale
3. Rotating  mount

Exercise 3. Measurement of the temporary resolution of the human eye

 The objectives of the exercise:

1. Familiarising students with the issue of light wave reception by the human eye, in particular the mechanism of stimulation of light receptors at the molecular level
2. Familiarising students with the mechanism of reception of light stimuli depending on the distance between sources and the duration of the pulse - spatial and temporary resolution
3. Determination of the maximum frequency of flickering of the light source, at which light is still perceived as discontinuous, as a function of the horizontal angle in bright light and in darkness
4. Analysis of the collected data and formulation of conclusions

1. Perimeter
2. Angular scale
3. Sine wave voltage generator
4. LED

Exercise 4. Determining diffusion potential

Exercise 5. Determination of the audibility threshold curve and the frequency discrimination threshold

 Exercise objectives:

1. Familiarising students with the issue of the propagation of the sound wave and the reception of sound wave through the human ear, in particular the role of the external ear in receiving and amplifying the sound
2. Familiarize students with objective and subjective characteristics of sound
3. Measurement of the human audibility threshold – the minimum audible intensity of the sound wave as a function of the frequency
4. Determination of the human ear threshold of discrimination between the frequencies – the smallest difference in sound frequency detectable by the student
5. Analysis of the collected data and formulation of conclusions

1. Cobra3 measurement module (connected to 12V power supply and computer)
2. Two-ear headphones
3. Sine wave generator

Exercise 6. Neurostimulator – study of nerve cell excitation

 Exercise goals:

1. Familiarization of students with the problem of generation of functional potential and propagation of nerve impulse.
2. Study of the shape of depolarization potential for various amplitudes, duration of stimulus and types of stimulated synapse.
3. Determination of the time constant of the membrane.
4. Analysis of the data collected and formulation of conclusions

1. Measuring module Cobra3
2. "Neurosimulator" unit
3. Power supply for the simulator

Exercise 7. Refractometry – measurement of the relationship between the concentration of the solution and the refractive index

 Exercise goals:

1. Familiarize students with the issue of electromagnetic wave propagation in the transparent medium and at the interface.
2. Familiarize students with the methodology of refractometric measurements and basic concepts of refractometry (dispersion, molar refraction, exaltation).
3. Familiarize students with the features, construction and principle of operation of Abbe refractometer.
4. Measurement of the refraction index for ethanol solutions at different concentrations. Determination of molar refraction and exaltation of the solution.
5. Analysis of collected data, estimation of measurement uncertainties and plotting of the chart.
6. Determination of unknown ethanol concentration in solution based on concentration dependent refraction plot.

1. main prism housing (upper, movable part),
2. measurement scale reading
3. eyepiece
4. light source
5. thermometer cover
6. thermometer display
7. scale knob
8. knob of the Amici compensator prisms