- The concentration of an undiluted sample is 26.4 mg/ml. Tocalculate that answer, the concentration of the diluted sample wasmultiplied by the dilution factor. Knowing that the dilution factoris 2, work backwards to determine the concentration of the DILUTEDsample.
| A. | 13.2 mg/ml |
| B. | 132.0 mg/ml |
| C. | 1.32 mg/ml |
| D. | 26.4 mg/ml |
What is the unit used to describe cell solutions measured in aspectrophotometer?
| | Cells/milliliter |
| | Grams (g) |
| | Optical density (OD) |
| | Meters (m) |
Spectroscopy is based on the ability of compounds tospecifically create certain wavelengths of light.
true or false
You are reading chlorophyll a samples in the spectrophotometerat 665 nm. Which of the following absorbance readings areconsidered to be inaccurate?
| | Abs 3.4 |
| | Abs 2.7 |
| | Abs 3.6 |
| | Abs 2.1 |
Ideally, a standard curve should be a curved line, not astraight line.
True
False
which of the following are common uses for a spectrophotometerin a biology lab? There may be more than one correct answer.
| A. | To quantify the activity of an enzyme |
| B. | To measure the concentration of protein in a cell sample. |
| C. | To quantify the density of cells in a population |
| D. | To quantify the amount of light-absorbing molecules in asample. |
Light with a wavelength of 600 nm is used to read the absorbanceof microbial cell cultures because cellular compounds (proteins,DNA, chromophores) absorb light at this wavelength and therefore donot interfere with the measurement.
True
False
The spectrophotometer output is in what units?
| | Absorbance (A or Abs) |
| | Nanometers |
| | Wavelengths |
| | None of the above |
Carrots appear orange in color because they are reflecting whatcolor of visible light?
