Unit : BiochemistryTopic : MicelleMatthayomsuksa 4

In aqueous solution, molecules having both polar or charged groups and non polar regions form aggregates called micelles. In a micelle, polar or ionic heads (hydrophilic) form an outer shell in contact with water, while non-polar tails (hydrophobic) are sequestered in the interior.

What is Micelle?

30 nm

The core of a micelle, being formed of long non polar tails, resembles an oil or gasoline drop. The length of the non-polar tail, the nature and size of the polar or ionic head, the acidity of the solution, the temperature, and the presence of added salts are the most important factors determining the kind of the obtained aggregate. If those parameters are changed, it is possible to change shape and size of the micelles.

What is Micelle?

hydrophilic “water-loving" something has a tendency to dissolve in or mix with water.

hydrophobic “water-fearing” lacking an affinity for water; unable to absorb, or be wetted by water.

Passive Voicesubject + auxiliary verb (be) + main verb (past participle)

We use the passive when:- we want to make the active object more important.- we do not know the active subject.

Example :

The core of a micelle, being formed of long non polar tails, resembles an oil

or gasoline drop.

Non polar tails are sequestered in the interior.

ColorChanging …Milk…

Let’s do the experiment!

Milk (whole or 2%) Dinner plate Food coloring Dish-washing soap Cotton swab

Materials

..Step by Step..

- Dish soap, because of its bipolar characteristics (nonpolar on one end and polar on the other), weakens the chemical bonds that hold the proteins and fats in solution.

- The soap's polar, or hydrophilic (water-loving), end dissolves in water, and its hydrophobic (water-fearing) end attaches to a fat globule in the milk.

- The molecules of fat bend, roll, twist, and contort in all directions as the soap molecules race around to join up with the fat molecules.

Does the type of milk change the outcome?

Can you do this with other liquids?

Will something other than this soap work?

Thank you..