Textbook Question
What nutritional type is a colorless microbe that uses the Calvin-Benson cycle, uses H₂ as the electron donor to its ETC, and uses elemental S as the final electron acceptor in the ETC?
1
views
Ch. 5 - Microbial Metabolism
Tortora14th EditionMicrobiology: An IntroductionISBN: 9780138200398
Not the one you use?Change textbookSelect a different textbook
Table of contents
- Ch. 1 - The Microbial World and You18
- Ch. 2 - Chemical Principles20
- Ch. 3 - Observing Microorganisms Through a Microscope18
- Ch. 4 - Functional Anatomy of Prokaryotic and Eukaryotic Cells21
- Ch. 5 - Microbial Metabolism20
- Ch. 6 - Microbial Growth20
- Ch. 7 - The Control of Microbial Growth20
- Ch. 8 - Microbial Genetics19
- Ch. 9 - Biotechnology & DNA Technology20
- Ch. 10 - Classification of Microorganisms15
- Ch. 11 - The Prokaryotes: Domains Bacteria and Archaea14
- Ch. 12 - The Eukaryotes: Fungi, Algae, Protozoa, and Helminths17
- Ch. 13 - Viruses, Viroids, and Prions20
- Ch. 14 - Principles of Disease and Epidemiology21
- Ch. 15 - Microbial Mechanisms of Pathogenicity19
- Ch. 16 - Innate Immunity: Nonspecific Defenses of the Host20
- Ch. 17 - Adaptive Immunity: Specific Defenses of the Host20
- Ch. 18 - Practical Applications of Immunology20
- Ch. 19 - Disorders Associated with the Immune System19
- Ch. 20 - Antimicrobial Drugs19
- Ch. 21 - Microbial Diseases of the Skin and Eyes21
- Ch. 22 - Microbial Diseases of the Nervous System19
- Ch. 23 - Microbial Diseases of the Cardiovascular and Lymphatic Systems20
- Ch. 24 - Microbial Diseases of the Respiratory System20
- Ch. 25 - Microbial Diseases of the Digestive System20
- Ch. 26 - Microbial Diseases of the Urinary and Reproductive Systems19
- Ch. 27 - Environmental Microbiology20
- Ch. 28 - Applied and Industrial Microbiology19
Tortora14th EditionMicrobiology: An IntroductionISBN: 9780138200398Not the one you use?Change textbook
Chapter 5, Problem 9
Use the following choices to answer the question.
a. E. coli growing in glucose broth at 35℃ with O2 for 5 days
b. E. coli growing in glucose broth at 35℃ without O2 for 5 days
c. Both a and b
d. Neither a nor b
Which culture uses NAD+ ?
Verified step by step guidance1
Step 1: Understand the role of NAD⁺ in cellular metabolism. NAD⁺ (nicotinamide adenine dinucleotide) is a coenzyme that acts as an electron acceptor in redox reactions, especially during glycolysis and cellular respiration.
Step 2: Identify the metabolic pathways used by E. coli under different oxygen conditions. When oxygen is present (aerobic conditions), E. coli performs aerobic respiration, where NAD⁺ is reduced to NADH during glycolysis and the Krebs cycle.
Step 3: Consider the anaerobic condition (without O₂). In the absence of oxygen, E. coli switches to fermentation or anaerobic respiration, which also requires NAD⁺ to accept electrons during glycolysis to keep the pathway running.
Step 4: Analyze the options: both aerobic (a) and anaerobic (b) growth require NAD⁺ to accept electrons during glycolysis, so both cultures use NAD⁺.
Step 5: Conclude that the correct choice is the one indicating that both cultures use NAD⁺, because NAD⁺ is essential for energy metabolism regardless of oxygen presence.
Verified video answer for a similar problem:
This video solution was recommended by our tutors as helpful for the problem above.
Video duration:
1mWas this helpful?
Key Concepts
Here are the essential concepts you must grasp in order to answer the question correctly.
Role of NAD⁺ in Cellular Metabolism
NAD⁺ (nicotinamide adenine dinucleotide) is a crucial coenzyme that acts as an electron carrier in metabolic reactions. It accepts electrons during the breakdown of glucose, becoming NADH, which then transfers electrons to the electron transport chain or other pathways to regenerate NAD⁺. This regeneration is essential for continuous glycolysis and energy production.
Recommended video:
Guided course
02:17
Introduction to Metabolism
Aerobic vs. Anaerobic Respiration in E. coli
E. coli can grow in both the presence and absence of oxygen. Under aerobic conditions, NADH donates electrons to oxygen via the electron transport chain, regenerating NAD⁺ efficiently. Under anaerobic conditions, E. coli uses fermentation or anaerobic respiration to regenerate NAD⁺, allowing glycolysis to continue despite the lack of oxygen.
Recommended video:
Guided course
03:35Anaerobic Respiration
Glucose Metabolism and NAD⁺ Utilization
During glucose metabolism, NAD⁺ is reduced to NADH in glycolysis and the Krebs cycle. For metabolism to continue, NADH must be oxidized back to NAD⁺. Both aerobic and anaerobic growth conditions require NAD⁺ to accept electrons, but the mechanisms of NAD⁺ regeneration differ depending on oxygen availability.
Recommended video:
Guided course
02:17Introduction to Metabolism
Related Practice
Textbook Question
Why must NADH be reoxidized? How does this happen in an organism that uses respiration? Fermentation?
2
views
Textbook Question
Write your own definition of the chemiosmotic mechanism of ATP generation. On Figure 5.16, mark the following using the appropriate letter:
a. The acidic side of the membrane
b. The side with a positive electrical charge
c. Potential energy
d. Kinetic energy
8
views
Textbook Question
Use the following choices to answer the question.
a. E. coli growing in glucose broth at 35℃ with O2 for 5 days
b. E. coli growing in glucose broth at 35℃ without O2 for 5 days
c. Both a and b
d. Neither a nor b
Which culture produces the most ATP?
Textbook Question
Use the following choices to answer the question.
a. E. coli growing in glucose broth at 35℃ with O2 for 5 days
b. E. coli growing in glucose broth at 35℃ without O2 for 5 days
c. Both a and b
d. Neither a nor b
Which culture uses the most glucose?
1
views