Quiz 5 (Lec. 8 & 9)

Does an increase in biomass necessarily mean an increase in bioproduct yield?

• No, the bioproduct must be purified from the biomass first

• No, bioproduct formation could be non-growth associated

• Yes, the bioproduct is typically a large portion of the biomass

• Yes, if protocol was followed

Cellular maintenance energy required by an organism is mostly spent towards:

• defense mechanisms

• secondary metabolism

• cellular growth

• osmotic & ionic balance

Tags

NGSS.HS-LS2-5

To determine cell viability, _______ dye is to used to stain the cell culture.

• Trypan blue

• Methylene blue

• Coomassie brilliant blue

• Phenol red

Calculate the doubling time given a viable cell count of 0.639 and 0.110 at 240 mins and 120 mins, respectively.

• 14 minutes

• 25.7 minutes

• 34.3 minutes

• 48 minutes

pH is a growth factor that can change due to:

• Utilization of substrate

• NH₄ production

• Cellular byproducts

• Cellular lysis/cell toxins

• All of the above

Which of the following statements regarding oxygen as a growth rate factor is false?

• O₂ can be a limiting substrate for aerobic fermentation

• O₂ is soluble in

  water and can be toxic to the cell culture

• Too much O₂ can be

  detrimental to cellular

  production

• Turbulence creates more opportunities for O₂ to diffuse

Tags

NGSS.HS-LS1-7

Which of the following is not a function of impellers in bioreactors?

• Helps maintain a uniform environment throughout the vessel contents

• Helps diminish the size of air bubbles

• Increases diffusion path

• Increases surface area for oxygen transfer

Which two substrates are limited in batch fermentation?

• Carbon & Oxygen

• Nitrogen & Ammonia

• Oxygen & Nitrogen

• Carbon & Nitrogen

In Chemostat fermentation, the culture is harvested at what rate compared to the rate feed material is added?

• slower

• faster

• equal

• 50% slower

What is the outcome in a continuous fermenter if the dilution rate is greater than the growth rate?

• Culture overgrowth

• Culture washes out

• Contaminated culture

• Steady state culture