Bioprocess Engineering Multiple Choice Questions on “Cell Nutrients”.
1. The Macronutrients concentration needed is __________
A. Greater than 10-2 M
B. Less than 10-2 M
C. Greater than 10 -4 M
D. Less than 10-4 M
Answer: C
Explanation: Macronutrients are needed in concentrations larger than 10-4 M. Carbon, nitrogen, oxygen, hydrogen, sulfur, phosphorus, Mg2+, and K+ are major macronutrients.
2. Which of the following components is not a Micronutrient?
A. Zn2+
B. Ca2+
C. Na+
D. Mg2+
Answer: D
Explanation: Elements used in large quantities by the plant are termed macronutrients, which can be further defined as primary or secondary. The primary nutrients include nitrogen (N), phosphorus (P), and potassium (K). These elements contribute to plant nutrient content, function of plant enzymes and biochemical processes, and integrity of plant cells. Deficiency of these nutrients contributes to reduced plant growth, health, and yield; thus they are the three most important nutrients supplied by fertilizers. The secondary nutrients include calcium (Ca), magnesium (Mg), and sulfur (S).
3. Viruses contain lipids.
A. True
B. False
Answer: A
Explanation: Viruses with a lipoprotein sheath may contain 25% lipid. Composition as a dry weight % includes <1.
4. Facultative autotrophs can grow under heterotrophic condition.
A. True
B. False
Answer: A
Explanation: Facultative autotrophs normally grow under autotrophic conditions; however, they can grow under heterotrophic conditions in the absence of CO2 and inorganic energy sources.
5. Which of the following can grow in absence of CO2 or carbon sources?
A. Autotrophs
B. Mixotrophs
C. Chemoautotrophs
D. Facultative autotrophs
Answer: D
Explanation: Facultative autotrophs normally grow under autotrophic conditions; however, they can grow under heterotrophic conditions in the absence of CO2 and inorganic energy sources.
6. Which of the following is the key element in the regulation of cell metabolism?
A. Hydrogen
B. Phosphorus
C. Oxygen
D. Nitrogen
Answer: B
Explanation: The main role of potassium is to provide the ionic environment for metabolic processes in the cytosol, and as such functions as a regulator of various processes including growth regulation. Plants require potassium ions (K+) for protein synthesis and for the opening and closing of stomata, which is regulated by proton pumps to make surrounding guard cells either turgid or flaccid. Phosphorus constitutes about 3% of cell dry weight and is present in nucleic acids and in the cell wall of some gram-positive bacteria such as teichoic acids. Phosphorus is a key element in the regulation of cell metabolism.
7. Which of the following ion is required by the ribosomes?
A. H+
B. Mg2+
C. Mn2+
D. Ca2+
Answer: B
Explanation: Magnesium, serves as a structural component and is involved as a cofactor in many enzymatic reactions. Magnesium is a component of the chlorophyll structure. Magnesium is required to maintain ribosome integrity. Ribosomes specifically require Mg2+ ions.
8. What do you mean by the term “Trace elements”?
A. Very small amount
B. Medium amount
C. High amount
D. Very high amount
Answer: A
Explanation: Trace elements are essential to microbial nutrition. Lack of essential trace elements increases the lag phase (the time from inoculation to active cell replication in batch culture) and may decrease the specific growth rate and the yield. A trace element is a chemical element whose concentration (or other measure of amount) is very low (a “trace amount”).
9. What is “EDTA”?
A. Magnesium calcium edentate
B. Nitrogen phosphorus edentate
C. Sodium calcium edentate
D. Magnesium phosphorus edentate
Answer: C
Explanation: A specific salt of EDTA, known as sodium calcium edetate, is used to bind metal ions in the practice of chelation therapy, e.g., for treating mercury and lead poisoning. It is used in a similar manner to remove excess iron from the body. EDTA is a chelating agent and a chelating agent is a substance whose molecules can form several bonds to a single metal ion. In other words, a chelating agent is a multidentate ligand.
10. Which of the following is not a defined media?
A. Glucose
B. Magnesium chloride
C. Calcium chloride
D. Phenyl acetic acid
Answer: D
Explanation: Defined media contain specific amounts of pure chemical compounds with known chemical compositions. A medium containing glucose, (NH4)2SO4, KH2PO4, and MgCl2 is a defined medium. Complex media contain natural compounds whose chemical composition is not exactly known. Complex medium used in penicillin fermentation includes Phenyl acetic acid by continuous feed in a concentration of about 0.5-0.8% of total (g/liter).
11. Which device is used to measure the amount of energy stored in foods?
A. Rheometer
B. Adiabatic calorimeter
C. Bomb calorimeter
D. Heat flow calorimeter
Answer: C
Explanation: Complex organic food molecules such as sugars, fats, and proteins are rich sources of energy for cells because much of the energy used to form these molecules is literally stored within the chemical bonds that hold them together. Scientists can measure the amount of energy stored in foods using a device called a bomb calorimeter. With this technique, food is placed inside the calorimeter and heated until it burns. The excess heat released by the reaction is directly proportional to the amount of energy contained in the food.
12. Complex carbohydrates which make up cell wall in plants are?
A. Lactose
B. Fructose
C. Cellulose
D. Sucrose
Answer: C
Explanation: Cellulose is a very important polysaccharide because it is the most abundant organic compound on earth. Cellulose is a major component of tough cell walls that surround plant cells, and is what makes plant stems, leaves, and branches so strong.
13. Micronutrient which is important in transport of sugar, synthesis of enzymes and cell division is?
A. Boron
B. Potassium
C. Calcium
D. Phosphorus
Answer: A
Explanation: Boron (B. is a micronutrient critical to the growth and health of all crops. It is a component of plant cell walls and reproductive structures. It is a mobile nutrient within the soil, meaning it is prone to movement within the soil. Because it is required in small amounts, it is important to deliver B as evenly as possible across the field. Boron plays a key role in a diverse range of plant functions including cell wall formation and stability, maintenance of structural and functional integrity of biological membranes, movement of sugar or energy into growing parts of plants, and pollination and seed set. Adequate B is also required for effective nitrogen fixation and nodulation in legume crops.
14. The minerals involved in water-splitting reaction during photosynthesis are ___________
A. Manganese and chloride
B. Magnesium and sulfur
C. Magnesium and potassium
D. Magnesium and phosphorus
Answer: A
Explanation: Water splitting is catalyzed by the oxygen-evolving complex (OEC. of protein complex photosystem II (PSII), producing dioxygen gas, protons and electrons. O (2) is released into the atmosphere, sustaining all aerobic life on earth; product protons are released into the thylakoid lumen, augmenting a proton concentration gradient across the membrane; and photo-energized electrons pass to the rest of the electron-transfer pathway. The OEC contains four manganese ions, one calcium ion and (almost certainly) a chloride ion.
15. Energy is measured in ________
A. Micronutrient
B. Macronutrient
C. Calories
D. Kilogram
Answer: C
Explanation: A calorie is a unit that is used to measure energy. The Calorie you see on a food package is actually a kilocalorie, or 1,000 calories. A Calorie (kcal) is the amount of energy needed to raise the temperature of 1 kilogram of water 1 degree Celsius.