LS4002 - Shapes of Biomolecules Lecture 8 - cis and trans isomers

Cis Double Bonds

Cis double bonds have substituents on the same side.

Trans Double Bonds

Trans double bonds have substituents on opposite sides.

Cis-Polyisoprene

A natural polymer found in rubber tree latex, featuring chains of C=C double bonds with substituents on the same side.

Trans-Polyisoprene

A polymer derived from Gutta-Percha, where double bonds have substituents on opposite sides, providing rigidity.

Vulcanization

A process where India rubber is heated with sulfur, forming cross-links between polymer chains to enhance elasticity and durability.

Squalene

A trans-alkene found in shark liver oil, serving as a precursor for cholesterol and steroid hormones.

Beta-Carotene

A provitamin A pigment essential for vision and immune function, found in carrots and colorful fruits.

Lycopene

A red pigment in tomatoes, studied for potential health benefits including cancer risk reduction.

Curcumin

A compound derived from turmeric, known for its anti-inflammatory and antioxidant properties.

D-Glucose

A sugar that exists in cis (beta) and trans (alpha) forms, influencing its physical properties and biological activities.

B-D-Glucose

The beta form of D-Glucose where the hydroxyl group on the first carbon is on the same side as the CH2OH group.

a-D-Glucose

The alpha form of D-Glucose where the hydroxyl group on the first carbon is on the opposite side from the CH2OH group.

Esterification

A chemical reaction that forms an ester from an alcohol and an acid, often producing water.

Hydrogenation

A chemical process that adds hydrogen to unsaturated fats, converting them into saturated fats.

Polymerization

The process of combining small molecules (monomers) into a larger, more complex structure (polymer).

Natural Rubber

A flexible polymer made from cis-polyisoprene, derived from the latex of rubber trees.

Thermoplastic

A type of plastic that becomes moldable upon heating and solidifies upon cooling.

Amphiphilic Molecules

Molecules that have both hydrophilic (water-loving) and hydrophobic (water-fearing) parts.

Lipid Bilayer

A double layer of phospholipids that forms the foundation of cell membranes.

Antioxidants

Compounds that protect cells from oxidation and damage by free radicals.

Cholesterol

A sterol molecule that is crucial for cell membrane structure and serves as a precursor for steroid hormones.

Carotenoids

A class of pigments in plants that provide colors and have antioxidant properties.

Amphiphilic Properties

Amphiphilic molecules can form micelles or lipid bilayers due to their dual affinity for water and lipids.

Micelle

A spherical arrangement of amphiphilic molecules where hydrophilic heads face outward and hydrophobic tails are sequestered inward.

Phospholipids

A type of lipid that is a major component of cell membranes, consisting of a hydrophilic head and two hydrophobic tails.

Unsaturated Fats

Fats that contain one or more double bonds, resulting in kinks in the fatty acid chains and a more fluid structure.

Saturated Fats

Fats that have no double bonds between carbon atoms, making them solid at room temperature.

Free Radicals

Unstable molecules that can cause oxidative damage to cells and are linked to various diseases.

Oxidation

A chemical reaction that involves the loss of electrons, often producing free radicals.

Dietary Fiber

Plant-based carbohydrates that are not digested in the small intestine, important for digestive health.

Cholesterol's Role

Cholesterol is essential for synthesizing vitamin D, bile acids, and various steroid hormones.

Natural antioxidants

Substances found in food, such as vitamins C and E, that help neutralize free radicals in the body.