Nokea
NAD and FAD are hydrogen carriers, but cytochromes are electron carriers in bacteria. What happens to the protons (Hâº) in electron transport chains?
- A. They go into solution inside the cytoplasm.
- B. They are taken back by NAD and FAD.
- C. They are carried from cytochromes to oxygen to form water.
- D. They go into solution outside the cytoplasmic membrane.
Correct Answer: D
Rationale: The correct answer is D because in the electron transport chain, protons (H⁺) are pumped across the membrane to create a proton gradient. This gradient is utilized by ATP synthase to produce ATP. Therefore, protons go into solution outside the cytoplasmic membrane. Choices A and B are incorrect because protons do not simply stay in the cytoplasm or get taken back by NAD and FAD. Choice C is incorrect as protons do not directly form water when carried by cytochromes.
You may also like to solve these questions
What is an example of an IV solution that would be appropriate to treat an extracellular fluid volume deficit?
- A. D5W
- B. 3% saline
- C. Lactated Ringer’s solution
- D. D5W in ½ normal saline (0.45%)
Correct Answer: C
Rationale: Lactated Ringer’s solution replenishes extracellular fluids and electrolytes effectively.
Treatment with two nucleoside reverse transcriptase inhibitors (NRTIs) and a protease inhibitor (PI) is prescribed for a patient with HIV infection who has a CD4+ T-cell count of <400/µL. The patient asks why so many drugs are necessary for treatment. What should the nurse explain as the primary rationale for combination therapy?
- A. Cross-resistance between specific antiretroviral drugs is reduced when drugs are given in combination.
- B. Combinations of antiretroviral drugs decrease the potential for development of antiretroviral-resistant HIV variants.
- C. Side effects of the drugs are reduced when smaller doses of three different drugs are used rather than large doses of one drug.
- D. When CD4+ T-cell counts are <500/µL, a combination of drugs that have different actions is more effective in slowing HIV growth.
Correct Answer: B
Rationale: Combination therapy minimizes the chance of developing resistant HIV strains by targeting the virus at multiple points in its lifecycle.
A patient had abdominal surgery 3 months ago and calls the clinic with complaints of severe abdominal pain and cramping, vomiting, and bloating. What should the nurse most likely suspect as the cause of the patient’s problem?
- A. Infection
- B. Adhesion
- C. Contracture
- D. Evisceration
Correct Answer: B
Rationale: Postoperative adhesions can form after abdominal surgeries, causing obstruction and symptoms such as pain, cramping, vomiting, and bloating. Adhesions are bands of fibrous tissue that develop during the healing process.
Choose the correct sequence in an allergic reaction.
- A. Allergen → mast cells → histamine → B cells → IgE antibodies
- B. Allergen → IgE antibodies → B cells → histamine → mast cells
- C. Allergen → B cells → IgE antibodies → mast cells → histamine
- D. Allergen → histamine → mast cells → IgE antibodies → B cells
Correct Answer: C
Rationale: Rationale for Answer C:
1. Allergen exposure triggers B cells to produce IgE antibodies specific to the allergen.
2. IgE antibodies bind to mast cells sensitizing them.
3. Upon re-exposure to allergen, allergen binds to IgE on mast cells.
4. This triggers release of histamine and other chemicals causing allergic symptoms.
Summary:
- Choice A: Incorrect because B cells do not produce IgE antibodies before allergen exposure.
- Choice B: Incorrect because IgE antibodies are produced by B cells, not the other way around.
- Choice D: Incorrect because histamine is released after allergen binds to IgE on sensitized mast cells.
Which historical event provides evidence for immune adaptation?
- A. Spanish flu pandemic
- B. The Black Death caused by Yersinia pestis
- C. HIV/AIDS epidemic
- D. The eradication of smallpox
Correct Answer: B
Rationale: The Black Death caused by Yersinia pestis is the correct answer because it led to immune adaptation in survivors. Yersinia pestis triggered the body to develop immunity. The Spanish flu pandemic, HIV/AIDS epidemic, and eradication of smallpox did not directly result in immune adaptation like the Black Death. The Spanish flu and HIV/AIDS were caused by viruses that did not lead to long-term immunity, and smallpox eradication was achieved through vaccinations, not natural immune adaptation.