Nursing Elites

1. What is the 'lock-and-key' model?

• A. Protein folding
• B. Enzyme-substrate interaction
• C. Muscle contraction
• D. Blood clotting

Correct answer: B

Rationale: The 'lock-and-key' model describes the specificity of the interaction between enzymes and their substrates. In this model, the enzyme's active site acts like a lock that can only be opened by the specific substrate molecule, which serves as the key. This specific binding ensures that enzymes catalyze particular reactions and do not interact with other molecules indiscriminately. Protein folding (option A) is the process by which a protein attains its functional three-dimensional structure but is not directly related to the lock-and-key model. Muscle contraction (option C) and blood clotting (option D) are complex biological processes but are not directly associated with the lock-and-key model of enzyme-substrate interaction.

2. Which is the correct order of formed elements in blood from smallest to largest cell size?

• A. Erythrocytes, thrombocytes, and leukocytes
• B. Thrombocytes, leukocytes, and erythrocytes
• C. Thrombocytes, erythrocytes, and leukocytes
• D. Leukocytes, erythrocytes, and thrombocytes

Correct answer: C

Rationale: The correct order of formed elements in blood from smallest to largest cell size is thrombocytes (platelets), erythrocytes (red blood cells), and leukocytes (white blood cells), making choice C the correct answer. Thrombocytes are the smallest, followed by erythrocytes, and then leukocytes. Choices A, B, and D are incorrect because they do not follow the correct order of cell size in blood formed elements.

3. What is the science of classifying organisms into different groups based on their evolutionary relationships called?

• A. Taxonomy
• B. Microbiology
• C. Genetics
• D. Epidemiology

Correct answer: A

Rationale: Taxonomy is the science of classifying organisms into different groups based on their evolutionary relationships. It involves identifying, naming, and categorizing living organisms according to their similarities and differences, helping us understand the diversity of life. Microbiology (option B) focuses on the study of microorganisms. Genetics (option C) deals with genes and heredity. Epidemiology (option D) explores the distribution and determinants of health-related states or events in populations. Therefore, the correct answer is Taxonomy as it specifically pertains to the classification of organisms based on their evolutionary relationships.

4. Which of the following is NOT a recommended method for preventing healthcare-associated infections (HAIs)?

• A. Handwashing with soap and water
• B. Proper use of personal protective equipment (PPE)
• C. Disinfecting and reusing sterile medical devices
• D. Using single-use sterile medical devices

Correct answer: C

Rationale: Disinfecting and reusing sterile medical devices is not a recommended method for preventing healthcare-associated infections (HAIs). Reusing sterile medical devices can increase the risk of infections due to inadequate sterilization or potential damage to the devices during the reprocessing process. Proper sterilization and disposal of single-use medical devices are essential in preventing the transmission of infections in healthcare settings. A) Handwashing with soap and water is a crucial method for preventing HAIs as it helps to remove and reduce the number of pathogens on the hands of healthcare workers, preventing the spread of infections. B) Proper use of personal protective equipment (PPE) such as gloves, gowns, masks, and eye protection is important in preventing the transmission of infections between patients and healthcare workers. C) Disinfecting and reusing sterile medical devices is not a recommended practice as it can lead to the transmission of infections if the devices are not adequately sterilized. Using single-use sterile medical devices helps to ensure that each patient receives a sterile device, reducing the risk of infections.

5. Which of the following enzymes is responsible for adding a nucleotide to a growing DNA chain?

• A. Helicase
• B. Ligase
• C. Nuclease
• D. Polymerase

Correct answer: D

Rationale: The correct answer is Polymerase. Polymerase is the enzyme responsible for adding nucleotides to a growing DNA chain during DNA replication. Helicase unwinds the DNA double helix to separate the DNA strands for replication, Ligase joins DNA fragments together by catalyzing the formation of phosphodiester bonds between them, and Nuclease cuts or degrades DNA strands. Therefore, choices A, B, and C are incorrect in the context of adding nucleotides to a growing DNA chain.

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