Chapter 35. Molecular Motors Flashcards
Substances, such as glucose, that, when present in the form of a gr adient, cause bacteria to swim toward the source of the gradient.
Chemoattractant
The process of moving in specific directions in response to environmental cues.
Chemotaxis
Proteolytic digestion products of myosin that are the force-generating units of the intact myosin molecule; the S1 fragment contains the ATPase and actin-binding sites.
S1 fragment
A bundle of microtubules which is composed of a peripheral group of nine microtubule pairs surrounding two singlet microtubules.
axoneme
The ability of the immune system to respond more rapidly and effectively to pathogens that have been encountered previously.
Immunological memory
Internal scaffolding of cells, made up of microfilaments, intermediate filaments, and microtubules, which enables cells to transport vesicles, change shape, and migrate.
Cytoskeleton
A bacterial flagellar protein that is part of the MS (membrane and supramembrane) ring; FliG, in combination with flagellar proteins MotA/MotB, forms a proton channel that drives the rotation of the flagellum.
FliG
A highly conserved protein found in all eukaryotes; in striated muscle, it forms the thin filaments of the sarcomere and activates the ATPase of myosin.
Actin
Actin monomers that come together to form filaments called F-actin.
G-actin
A property of microtubules such that some microtubules in a population lengthen while other simultaneously shorten; a result of the random fluctuations in the number of GTP- tubulin subunits or GDP-tubulin subunits at the ends of the microtubule. GTP-tubulin polymerizes more readily.
Dynamic instability
A short segment of kinesin that binds to the head domain of kinesin when ATP is bound and is released when the nucleotide-binding site is vacant or occupied by ADP.
Neck linker
A filament of G-actin monomers that is a polar, self-assembling, dynamic polymer.
F-actin
Vaccines that contain pathogens that have been rendered harmless by treatment with chemicals or high heat.
Killed, or inactivate, vaccines
A protein that forms the thick filaments of striated muscle; displays ATPase activity at its globular head, which, in conjunction with the ability to reversibly bind actin at its fibrous region, provides the power stroke of muscle contraction.
Myosin
A long helix that connects the switch regions of the S1 fragment to the lever arm; the nature of the nucleotide in the S1 fragment (ATP or ADP) allows the relay helix to change position, resulting in a reorientation of the lever arm.
Relay helix