MIM4

Question 1

What is the origin of entropic elasticity? Why does a polymer coil up?

Answer 1

Entropy favors a coiled state due to increased randomness.

Question 2

How is toughness in collagen and keratin achieved?

Answer 2

Achieved through hierarchical structures and covalent cross-links.

Question 3

What is the most common quaternary structural motif of biological protein materials?

Answer 3

Coiled-coil motif is most common.

Question 4

What is the role of covalent cross-linking in protein materials?

Answer 4

Provides mechanical stability and resilience.

Question 5

What is the role of the cytoskeleton?

Answer 5

Maintains cell shape and supports intracellular transport.

Question 6

What are the different roles of collagen and elastin in skin?

Answer 6

Collagen provides strength; elastin provides elasticity.

Question 7

What is the role of biopolymers in bacterial biofilms?

Answer 7

Biopolymers protect bacteria and aid in adhesion.

Question 8

Why is biofilm formation problematic?

Answer 8

Biofilms resist antibiotics and host defenses.

Question 9

What are potential applications for spider silk?

Answer 9

Medical sutures, textiles, and biomaterials.

Question 10

Know some examples of biological composite materials and their function.

Answer 10

Bone (strength) and nacre (toughness) are examples.

Question 11

How does DNA origami work and what can it be used for? What are disadvantages of DNA origami?

Answer 11

Folds DNA into shapes; used in nanotech; costly and slow.

Question 12

Why do rod-like particles form liquid crystals?

Answer 12

Rod-like particles align due to anisotropic interactions.

Question 13

What are the components of wood?

Answer 13

Cellulose, hemicellulose, and lignin.

Question 14

How can a Brownian ratchet convert thermal into mechanical energy?

Answer 14

Thermal energy drives directional motion via ratchets.

Question 15

What is the free energy of ATP hydrolysis mostly used for in molecular motors?

Answer 15

Powers conformational changes and transport processes.

Question 16

What is the scallop theorem and what consequences does it have for microswimmers?

Answer 16

Low-Reynolds-number motion constraints microswimmers.

Question 17

What are the main types of molecular motors and what do they do?

Answer 17

Kinesin, dynein, myosin; transport and contraction.

Question 18

How can a translational motor create a beating motion?

Answer 18

Wave-like motion from periodic structural changes.

Question 19

How can motion be achieved in artificial microstructures (examples)?

Answer 19

Via actuation, thermal gradients, or magnetic fields.

Question 20

How do muscles work (roughly)?

Answer 20

Contraction via actin-myosin interactions.

Question 21

Be able to calculate force of polymerisation motor from molecular dimension of building block and free energy of addition.

Answer 21

Force = (molecular dimension x free energy) per block.

Question 22

Be able to estimate energy efficiency of molecular motor from ATP consumption and work performed.

Answer 22

Efficiency = Work performed / ATP energy used.

Question 23

Be able to estimate torque of molecular motor from step size and ATP consumption.

Answer 23

Torque = (Step size x ATP energy) / rotational distance.