BIOL 107 Chapter 3: Lipids & Glycolipids

Flashcards covering key vocabulary related to Lipids and Glycolipids from Chapter 3 of the BIOL 107 lecture notes.

Lipids

Important biological components with various roles, including structural components, energy storage, and signaling molecules. They are characterized by being hydrophobic.

Triglycerides (Fats and Oils)

A main type of lipid primarily used for energy storage, formed by joining fatty acids and glycerol via an ester linkage through a dehydration reaction.

Phospholipids

Also known as membrane lipids, found in cell membranes. They are amphipathic, possessing a hydrophilic phosphate head and hydrophobic fatty acid tails, which allows them to naturally form membranes in water.

Steroids

Lipids important in membranes and as signaling molecules (hormones). Their structure features four fused carbon rings, conferring rigidity and a planar shape.

Hydrophobic

A common biochemical property among lipids, meaning they repel water.

Fatty Acids

A main component of fats, consisting of a polar carboxyl head and a non-polar hydrocarbon tail (typically 16 to 18 carbons long).

Glycerol

A main component of fats, which joins with fatty acids via an ester linkage formed by a dehydration reaction.

Ester linkage

The chemical bond formed between fatty acids and glycerol through a dehydration or condensation reaction to create a fat molecule.

Carboxyl head

The polar and hydrophilic part of a fatty acid molecule.

Hydrocarbon tail

The non-polar and hydrophobic part of a fatty acid molecule, typically consisting of 16 to 18 carbon atoms.

Saturated fatty acids

Fatty acids characterized by only single bonds between carbons in their hydrocarbon tail, resulting in a straight chain structure. They are commonly found in animals and are solid at room temperature.

Unsaturated fatty acids

Fatty acids that contain one or more double bonds between carbons in their hydrocarbon tail. They are common in plants and are liquid at room temperature, and can have cis or trans configurations.

Cis configuration

A specific arrangement around a double bond in an unsaturated fatty acid, causing the hydrocarbon tail to have a kink rather than remaining straight.

Amphipathic

A property of phospholipids, meaning they possess both hydrophobic (water-repelling fatty acid tails) and hydrophilic (water-attracting phosphate heads) parts.

Cholesterol

A type of steroid found in animal cell membranes. It acts as a buffer against extremes in membrane fluidity, stabilizing it at high temperatures and maintaining fluidity at low temperatures. It is also a precursor for hormones.

Waxes

Lipids formed by an ester linkage between a long-chain alcohol and a long-chain fatty acid. They have various functions and are known for their water-repellent texture.

Glycolipids

Lipids composed of a sphingosine scaffold with a sugar unit as a 'head group.' They are found in cell membranes and play a role in cell-cell interactions, often located on the external cell surface.

Liposome

One of the membrane structures that phospholipids can form in an aqueous solution, characterized as a sphere of lipid bilayer enclosing an aqueous compartment.

Micelle

One of the membrane structures that phospholipids can form in an aqueous solution, where hydrophobic tails aggregate inward and hydrophilic heads face outward, forming a spherical shape.

Bilayer sheet

One of the membrane structures that phospholipids can form in an aqueous solution, consisting of a double layer with hydrophobic tails facing each other and hydrophilic heads facing outwards towards the aqueous environment.