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TLS Online TPP Program

#Question id: 626

A metabolic pathway proceeds according to the scheme, R -> S -> T -> U -> V -> W.  A regulatory enzyme, X, catalyzes the first reaction in the pathway.  Which of the following is most likely correct for this pathway?

#Section 2: General Biology

  1. Either metabolite U or V is likely to be a positive modulator, increasing the activity of X.

  2. The first product S, is probably the primary negative modulator of X, leading to feedback inhibition.

  3. The last product, W, is likely to be a negative modulator of X, leading to feedback inhibition.

  4. The last product, W, is likely to be a positive modulator, increasing the activity of X.

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TLS Online TPP Program

#Question id: 21161

#Section 5: Bioprocess Engineering and Process Biotechnology

If CA is the quantity of reactants initially present, the quantity left after 'n' half periods will be equal to
TLS Online TPP Program

#Question id: 15017

#Section 1: Engineering Mathematics

 

Then ABC =
TLS Online TPP Program

#Question id: 1977

#Section 2: General Biology

A patient can produce antibodies against some bacterial pathogens, but he does not produce antibodies against viral infections. This is probably due to a disorder in which cells of the immune system?
TLS Online TPP Program

#Question id: 14248

#Section 5: Bioprocess Engineering and Process Biotechnology

A steam steriliser is used to sterilise liquid medium for fermentation. The initial concentration of contaminating organisms is 108 per litre. For design purposes, the final acceptable level of contamination is usually taken to be 10-3cells; this corresponds to a risk that one batch in a thousand will remain contaminated even after the sterilisation process is complete. For how long should 1 m3 medium be treated if the temperature is 140⁰C ________________.

        To be safe, assume that the contaminants present are spores of Bacillus stearothermophilus, one of the most heat-resistant microorganisms known. For these spores the activation energy for thermal death is 283 kJ gmo1-1 and the Arrhenius constant is 1036.2 s-1

TLS Online TPP Program

#Question id: 14564

#Section 2: General Biology

The lag phase of the bacterial growth curve is marked by