Question

A spectrophotometer can measure the amount of light absorbed by a solution. A cloudy solution absorbs more light than a clear solution. What should happen to the absorption reading of a bacterial solution that is treated with lysozyme? and Why? (See appendix B for more information about spectrophotometry). (Hint: What should be the appropriate word for describing absorption reading value?) Absorption reading will decrease due to less light absorption by lower bacterial population. Absorption reading will remain constant because lysozyme will only kill some bacteria. Absorption reading will get more cloudy since bacterialyse and the cellular structures are everywhere in the solution Absorption reading will increase because the wavelength gets longer. Absorption reading will get clearer because more bacteria lysed in the solution Absorption reading will keep fluctuate (goes up and down) because the bacterial population is unstable in the solution.

Answer 1

Answer 1: Absorption reading will decrease due to less light absorption by lower bacterial population.

Explanation: Lysozyme is an enzyme found in the body secretions. The enzyme is capable of killing the bacteria by hydrolysing the bond present between N-acetyl muramic acid and N-acetyl glucosamine present in peptidoglycan layer of the cell wall of bacteria.(Lysozyme acts only against Gram positive bacteria. As the Gram negative bacteria has a outer wall of lipid bilayer present over the peptidoglycan layer, lysozyme can not penetrate till the peptidoglycan layer).

The absorbance reading will decrease since the killing of bacteria by lysozyme will result in decrease in the turbidity of the suspension.

Answer 2:The appropriate word for absorption reading is ‘absorbance’