Polarity and Solubility of Molecules

Polarity and Solubility of MoleculesTo complete this worksheet, select: Module: Foundations Activity: Animations Title: Polarity and Solubility of Molecules Introduction1. Why is water the perfect medium to transport other molecules? Many substances can dissolve in water due to the polar nature of the water molecule. 2. Explain why water molecules are polar. The unequal distribution of charges give the molecule its polarity. 3. Explain how water molecules dissolve the following: ionized or polar molecules – polar water molecules are attracted to ions and dissolve them. organic molecules (carbohydrates, proteins, nucleic acids, ATP) - Polar covalent molecules can easily be dissolved- such as carbohydrates, proteins and nucleic acids. Explain why nonpolar molecules do not dissolve in water. The electron of nonpolar covalent compounds are uniformity distributed. Since they have no charge and are not attracted to water they cannot dissolve. 5. Describe how lipids respond in water. Lipids are insoluble in water both in or outside the cell.Phospholipids have non polar and polar ends.Because the heads are polar theymix with water (hydrophilic). They are insoluble because they are not charged, and since they are not charged they are neither repelled nor attracted to the water molecule. Rather, they react with water as a separate interface. 6. Explain the unique structure of phospholipid molecules and explain their importance in membrane structure. The polarity of the phospholipid, that being the insoluble lipid end and the soluble phosphate end, provides a waterproof barrier for the cell membrane.