Proton Motive Force via DIRK


Estimates the proton motive force through the ATP synthase, thereby estimating ATP production. The proton motive force is measured by measuring the electrochromic shift (ECS), the shift in the absorbance of chlorophyll at ~520nm in the thylakoid membrane due to a shift in the electric field. The electric field is created by the accumulation of hydrogen ions (H+) in the thylakoid, causing an electric field to be produced between the inside and outside of the thylakoid membrane. This measurement applies the ambient light level in the chamber to the sample, then shuts off the light, causing the intensity of the electric field to drop as the H+ ions drain from the thylakoid. This drop in electric field intensity is detected by the measuring light at 520nm. The method is called DIRK - Dark Induced Relaxation Kinetics. The size of the change in the electric field (and therefore 520 signal) is an indicator of the quantity of H+ ions which had accumulated in the thylakoid. The rate at which the electric field changes indicates the capacity of ATP synthase to release H+ from the thylakoid membrane.

[
  {
    "pulses": [
      5000,
      300,
      300,
      300
    ],
    "environmental": [
      [
        "light_intensity",
        0
      ]
    ],
    "act_background_light": 20,
    "tcs_to_act": 100,
    "protocols": 1,
    "averages": 4,
    "averages_delay": 0,
    "pulsesize": 10,
    "pulsedistance": 1000,
    "act1_lights": [
      20,
      20,
      0,
      20
    ],
    "act_intensities": [
      -1,
      -1,
      0,
      -1
    ],
    "meas_intensities": [
      2400,
      2400,
      2400,
      2400
    ],
    "detectors": [
      [
        35
      ],
      [
        35
      ],
      [
        35
      ],
      [
        35
      ]
    ],
    "meas_lights": [
      [
        0
      ],
      [
        16
      ],
      [
        16
      ],
      [
        16
      ]
    ],
    "protocols_delay": 0
  }
]
012409 pbi 160 low low res headshot
Created by

Greg Austic


Category

Plants

Compatible Instruments

MultispeQ beta


Latest Update

Jun 2016