There is evidence that the accumulation of abnormal or damaged proteins due to impairment of the pathway contributes to a number of neurodegenerative diseases, including Alzheimer’s. In contrast, deliberately blocking the pathway in cancer cells could lead to a disruption of protein regulation that in turn could cause the apoptosis of the malignant cells. Accordingly, proteasome inhibitors have been developed for evaluation as anti-tumour agents against selected cancers. Bortezomib is one such inhibitor that targets the 26S proteasome, and in combination with other chemotherapeutic agents has been shown to have therapeutic potential. In contrast to the long-term control, there are several mechanisms by which the activity of an enzyme can be altered almost instantaneously:

A. Reversible inhibition by small molecules (drugs)

B. Product inhibition

C. Allosteric regulation

D. Reversible covalent modification

Which of the above mechanism follow the process of negative-feedback control and ADP-ribosylation respectively?

TLS Online TPP Program

#Question id: 21054

#Unit 12. Biochemical Engineering

Zymomonas mobilis is cultivated in a 60 l chemostat. The μmax and Ks values are 0.2 h^-1 and 0.5 g l^-1 respectively. The flow rate (l h^-1) required for a steady state substrate concentration of 0.5 g l-1 in the reactor is:

TLS Online TPP Program

#Question id: 21057

#Unit 12. Biochemical Engineering

Two organisms A and B with the same μmax and Yx/s are cultivated independently in batch culture. They have Ks values of 1 g.l-1 and 3 g.l-1 respectively. Given that the initial substrate concentration was 5 g/l, which of the following is TRUE after complete exhaustion of the substrate?

TLS Online TPP Program

#Question id: 20819

#Unit 12. Biochemical Engineering

A microorganism following Monod kinetics is grown in a chemostat with working volume of 5 L and inlet substrate concentration of 1g/L. If the μmax and Ks of the organism are 0.5 h-1 and 0.25g/L respectively, washout occurs when the flow rate (L.h-1) exceeds

TLS Online TPP Program

#Question id: 20822

#Unit 12. Biochemical Engineering

A high cell density fermentation produces recombinant protein product which is 20% of the total cellular protein. The final cell density is 80 OD (1 OD = 0.4g of dry cell wt/L of which 50% is total cellular protein). Then the product concentration (g/L) is:

TLS Online TPP Program

#Question id: 20831

#Unit 12. Biochemical Engineering

A culture can grow independently in two carbon sources, glucose and hexadecane. Identify which one of the following statements is TRUE?

TLS Online TPP Program

#Question id: 20835

#Unit 12. Biochemical Engineering

In a batch microbial fermentation process the dissolved oxygen concentration (DOC) remains almost zero during growth. Which of the following methods will you use for the estimation of oxygen transfer rate while the fermentation is in progress?