Interesting Application of ALKANES and ALKENES Saturated Saturated

Interesting Application of ALKANES and ALKENES

Saturated • Saturated molecules are made entirely of single carbon-carbon bonds; • Alkanes are saturated. • Saturated fats usually solids and are most prevalent in substances such as lard, butter, red meats. • The most common saturated fats are palmitin (an ester of palmitic acid) and stearin (an ester of stearic acid) Butyric Acid (Butter fat). • The consumption of saturated fats is directly related to Heart disease, the clogging of arteries and the increase of cholesterol in the blood.

Unsaturated • Unsaturated molecules occur when double bonds or triple bonds are found between carbon atoms, • Alkenes (double bonds) and Alkynes (Triple bonds) are unsaturated. • There is a possibility for braking these multiple bonds and introducing additional atoms into the molecule creating a saturated molecule or breaking the molecule apart. • Beneficial for the body • Commonly found in oils produced by plants or fish. • The most common unsaturated fats are olein (an ester of oleic acid) and linoleic acid (a poly unsaturated oil found commonly in soybean oil)

Fatty Acids

Question? • Why is it that saturated fats are bad for the body and unstaturated fats especially polyunsaturated fats are recommended by dieticians and doctors? • The body can not process saturated fats and they tend to precipiate out in the blood stream where as the unsaturated molecules can be broken down because of the presence of multiple bond • The consumption of saturated fats is directly related to Heart disease, the clogging of arteries and the increase of cholesterol in the blood.

Consuming too many saturated fats leads to…. • Arthrosclerosis

Stereoisomers / Geometric Isomers • Where double bonds exist there are two possible spacial orientations for the adjacent groups. • Cis -adjacent groups are located on the same side of the double bond. • Trans -adjacent groups are located on alternates sides of the double bond.

Significance of Isomers • Even though the molecular formula remains the same the identity and the physical and chemical characteristics of the substance changes because of the spatial arrangement. • The importance of the geometric shape of the molecule can be illustrated by the function of chemical receptors in the human body, and the activity of enzymes, hormones, and vitamins.

The Black Pepper Problem • Why does freshly ground pepper have so much more zest than bulk pre-ground pepper? • The difference is between cis and trans isomers of the molecule Chavicine. Over time the freshly ground zesty cis isomers revert back to the more stable tasteless trans form. • This change is a chemical reaction that is caused by the heat energy in the room.

Eye See • The function of the eye relies on cis / trans isomers. • Retinal, a light sensitive molecule when stimulated by light chemically changes from cis to trans isomer form. • This initiates a signal in the optic nerve which is then transmitted to the brain. • This is a reversible chemical reaction that is caused by light & or heat.

Trans Fats • Found in everything made from hydrogenated oils or shortening

Explanation • When oils are made into solids such as margarine or shortening by the process of hyrogenation, unsaturated fats are saturated and the cis forms of fatty acids turn into the trans form • Trans fats tend to stick together better leading to clogged arteries • Trans become harder for the body’s enzymes to break down due to the shape change