An activated-sludge waste treatment system is required to reduce the amount of BOD₅ from 1000 mg/l to 20 mg/l at the exit. The sedimentation unit concentrates biomass by a factor of 3. Kinetic parameters are µ_m = 0.2 h-1 , K_s = 80 mg/l, k_d = 0.01 h-1 , and Y ^M _X/S = 0.5 g MLVSS/g BOD₅. The flow of waste water is 10000 l/h and the size of the treatment basin is 50,000 l. What is the value of the solids residence time?

#Question id: 11206

#Part-B Specialized Branches in Biotechnology

Tetrodotoxin blocks voltage-gated sodium channels, and ouabain blocks sodium-potassium pumps. If you added both tetrodotoxin and ouabain to a solution containing neural tissue, what responses would you expect?

#Question id: 11207

#Part-B Specialized Branches in Biotechnology

In multiple sclerosis, the myelin sheaths around the axons of the brain and spinal cord are damaged and demyelination results. How does this disease manifest at the level of the action potential?

 I) Action potentials move in the opposite direction on the axon.

 II) Action potentials move more slowly along the axon.

 III) No action potentials are transmitted.

#Question id: 11208

#Part-B Specialized Branches in Biotechnology

Neurotransmitters are released from axon terminals via ________.

#Question id: 11209

#Part-B Specialized Branches in Biotechnology

Acetylcholine released into the junction between a motor neuron and a skeletal muscle binds to a sodium/potassium channel and opens it. This is an example of ________.

#Question id: 11210

#Part-B Specialized Branches in Biotechnology

An inhibitory postsynaptic potential (IPSP) occurs in a membrane made more permeable to ________.

#Question id: 11212

#Part-B Specialized Branches in Biotechnology

The activity of acetylcholine in a synapse is terminated by its ________.