MIM4 Flashcards
What is the origin of entropic elasticity? Why does a polymer coil up?
Entropy favors a coiled state due to increased randomness.
How is toughness in collagen and keratin achieved?
Achieved through hierarchical structures and covalent cross-links.
What is the most common quaternary structural motif of biological protein materials?
Coiled-coil motif is most common.
What is the role of covalent cross-linking in protein materials?
Provides mechanical stability and resilience.
What is the role of the cytoskeleton?
Maintains cell shape and supports intracellular transport.
What are the different roles of collagen and elastin in skin?
Collagen provides strength; elastin provides elasticity.
What is the role of biopolymers in bacterial biofilms?
Biopolymers protect bacteria and aid in adhesion.
Why is biofilm formation problematic?
Biofilms resist antibiotics and host defenses.
What are potential applications for spider silk?
Medical sutures, textiles, and biomaterials.
Know some examples of biological composite materials and their function.
Bone (strength) and nacre (toughness) are examples.
How does DNA origami work and what can it be used for? What are disadvantages of DNA origami?
Folds DNA into shapes; used in nanotech; costly and slow.
Why do rod-like particles form liquid crystals?
Rod-like particles align due to anisotropic interactions.
What are the components of wood?
Cellulose, hemicellulose, and lignin.
How can a Brownian ratchet convert thermal into mechanical energy?
Thermal energy drives directional motion via ratchets.
What is the free energy of ATP hydrolysis mostly used for in molecular motors?
Powers conformational changes and transport processes.
What is the scallop theorem and what consequences does it have for microswimmers?
Low-Reynolds-number motion constraints microswimmers.
What are the main types of molecular motors and what do they do?
Kinesin, dynein, myosin; transport and contraction.
How can a translational motor create a beating motion?
Wave-like motion from periodic structural changes.
How can motion be achieved in artificial microstructures (examples)?
Via actuation, thermal gradients, or magnetic fields.
How do muscles work (roughly)?
Contraction via actin-myosin interactions.
Be able to calculate force of polymerisation motor from molecular dimension of building block and free energy of addition.
Force = (molecular dimension x free energy) per block.
Be able to estimate energy efficiency of molecular motor from ATP consumption and work performed.
Efficiency = Work performed / ATP energy used.
Be able to estimate torque of molecular motor from step size and ATP consumption.
Torque = (Step size x ATP energy) / rotational distance.
