Understanding Hydrophobic Effects and Stereoisomerism in Chemistry
Classified in Chemistry
Written at on English with a size of 3.32 KB.
Q: Explain in detail the interaction of hydrophobic or hydrophobic effect. Is it a chemical bond? Explain your answer. Discuss the importance of this phenomenon in the formation and stability of biological membranes.
Hydrophobic Effect: The tendency of nonpolar molecules to cluster in polar solvents like H2O for energetic reasons. Nonpolar substances tend to associate with one another in aqueous solutions because this results in fewer water molecules being involved in the cage that surrounds them. This situation is thermodynamically favored as it leads to lower order due to fewer water molecules (i.e., the entropy is higher) compared to when each polar molecule is surrounded by individual water molecules.
It is a chemical bond since it is not any kind of electrostatic interaction between atoms or molecules.
Biological membranes are primarily formed because lipids have long nonpolar hydrocarbon chains. These lipids tend to associate in an aqueous medium due to the initial hydrophobic effect. Once partners come into play, weak London dispersion interactions tend to bind and stabilize these groups of lipids.
Explain when two molecules are isomers or stereoisomers. Describe in detail two different types of stereoisomerism.
Two molecules can have the same molecular formula but differ in the spatial arrangement of their atoms and not in the sequence of bonding between them.
The two basic types are optical and geometric isomers (cis-trans).
The optical configuration arises from the existence of chiral or asymmetric carbon atoms, which have four different substituents. Around these carbons, we can have two different arrangements of the four substituents in space, resulting in different optical isomers.
Geometric isomerism is due to the presence of double bonds in the molecules, which prevent free rotation. Therefore, the four substituents of the two carbons linked by a double bond can be oriented in two different ways in space (cis and trans).
Nucleophile (lover of the core): An electron-rich reagent that can form bonds by donating a pair of electrons to an electron-deficient site.
Electrophile (electron affinity): An electron-deficient reagent that can form a bond by accepting an electron pair from a nucleophile.
Carbocation: A positively charged organic ion on a carbon atom, formed from a heterolytic cleavage of a C-H bond in an organic molecule. It is a carbon with an sp2 pz orbital that is empty.
Carbanion: A negatively charged organic ion on a carbon atom, formed from a heterolytic cleavage of a C-H bond in an organic molecule. It is a carbon with an sp2 pz orbital that contains two electrons.
Carbon Radical: Each of the groups that occur when a molecule is broken in a homolytic manner, taking an electron from a bond. It is a carbon with an sp2 pz orbital that contains one electron.