Spectrophotometer

Definition

A spectrophotometer is an instrument that measures the amount of light absorbed by a sample at different wavelengths. It is essential for analyzing the absorption spectra of pigments involved in photosynthesis.

5 Must Know Facts For Your Next Test

1. The spectrophotometer quantifies the light absorption of chlorophyll and other pigments.
2. It helps determine the specific wavelengths of light most effectively used in photosynthesis.
3. Absorption spectra obtained from a spectrophotometer can show peaks corresponding to chlorophyll's optimal absorbance wavelengths.
4. This tool can be used to measure changes in pigment concentration during various stages of photosynthesis.
5. Calibration with a blank sample is necessary to ensure accurate measurements.

Review Questions

• What does a spectrophotometer measure?
• How does a spectrophotometer help in studying photosynthesis?
• Why is calibration important when using a spectrophotometer?

Related terms

Chlorophyll:

A green pigment found in plants that absorbs light to provide energy for photosynthesis.

Absorption Spectrum: A graph plotting a pigment’s light absorption versus wavelength.

Light-Dependent Reactions: The set of reactions in photosynthesis that convert solar energy into chemical energy as ATP and NADPH.