Lipids and Biomembranes

Flashcards covering the structure, types, and properties of lipids and biomembranes as discussed in MCB 150 Lecture 5.

Lipids

Defined by a physical property, not a chemical structure, vary widely in structure. Primary functions include energy storage, biomembrane composition, and chemical signaling. Four primary types are triglycerides, phospholipids & glycolipids, and steroids.

Glycerol and Fatty Acids

The monomers of (biological membrane) lipids.

Triglyceride

3 Fatty Acids + Glycerol.

Phospholipid

2 Fatty Acids + Glycerol + Phosphate.

Phospholipids

Have variety in polar head groups and fatty acid tails that can vary in length and degree of saturation. They are also amphipathic.

Micelles or Bilayers

Formed spontaneously when phospholipids are in water.

Liposomes

Formed when bilayers have exposed edges and fold.

Glycolipids

Some membrane lipids are this.

Steroids

Can be used as circulating hormones or as membrane components. Animal cells have cholesterol in their biomembranes. Plants & fungi: different steroids; bacteria: none

Biomembranes

Are Asymmetrical and have associated Proteins (Transmembrane, Membrane-associated, Lipid-linked, Peripheral).

Proteins in Biomembranes

Serve a variety of functions including transport, enzymatic activity, signal transduction, cell-cell recognition, intercellular joining, and attachment to the cytoskeleton and extracellular matrix (ECM).

Biomembranes

Are Selectively Permeable.