• Band 3
  • A transmembrane protein of 100,000 molecular weight isolated from the red blood cell membrane. It is so named because it was originally detected as the third band on an SDS gel.
• Bilayer Sheets
  • Two sheets of molecules sandwiched together. Bilayer sheets are often used in reference to the phospholipid bilayer of cell membranes.
• Bile Acids
  • Amphipathic molecules found in the bile secreted by the liver. The primary bile acids in human bile are taurocholic acid and glycocholic acid, which aid in fat emulsification and digestion.

Bip (Binding Protein): A chaperone and resident endoplasmic reticulum protein. It is structurally related to the hsp70 proteins and recognizes incorrectly folded proteins. Bip may also help pull proteins into the endoplasmic reticulum.

Bivalent: Possessing two binding sites, such as those that occur on an antibody.

Black Membrane: An experimental membrane produced between two water reservoirs. Black membranes were used to understand the structure and function of biological membranes. The black nature is due to light interference patterns.

Blastomeres: Cells produced by the cleavage of an egg subsequent to fertilization.

Bright-Field Microscope: A type of microscope used primarily to examine fixed (dead) and stained samples. It is the oldest of the light microscope systems.

Bright-Field: A term used in conjunction with bright-field microscopy. Bright-field microscopy is used primarily to examine fixed (dead) and stained samples. It is the oldest of the light microscope systems.