The molar absorptivity of a tyrosine residue at 280 nm is 2000 M-1cm-1, while for tryptophan it is 5500 M-1cm-1. A protein has been isolated that is known to contain one tyrosine residue and an unknown number of tryptophans. A 1.0 micromolar solution of this protein is placed in a 1.0 cm cuvette and the absorbance at 280 nm is measured as 0.024. How many tryptophans are in the protein

There are 4 tryptophans in the protein.

Explanation:

According to question,  protein contains one tyrosine residue and say x number of tryptophans.

Concentration of protein solution = 1.0 micromolar =

Molar absorptivity of a protein solution :

Length of the cuvette = l = 1.0 cm

Absorbance of protein solution at 280 nm = A = 0.024

( Beer-Lambert's law)

Solving for x :

x = 4

There are 4 tryptophans in the protein.

water   molecules stay close to each other through cohesion, the collective action of hydrogen bonds between water molecules. cohesion plants draw water upwards from the root through the stem's transport tubes (xylem) to the leaf. this transport occurs even in large trees and against gravity. transpiration, evaporation of water from plant leaves, creates a tension on water molecules being pulled up from the stem and roots.

water also has high (the attraction of one substance to another) properties because of its polar nature. adhesion of water molecules to plant cell walls counteract gravity while water is transported from roots to leaves.

water exhibits a very high surface tension when compared to other liquids. surface tension is a property of a liquid that holds the surface together and allows it to resist an external force. by capillary action, the water forms concave menisci inside the pores. the high surface tension of water pulls the concavity outwards, generating enough force to lift water from the roots to the leaves of plants.

thus, cohesion, along with adhesion and surface tension creates a capillary action that keeps water molecules interacting and moving through the plants out to the leaf cells.

therefore, option d) is the correct answer.

explanation:

c. is the answer

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