Nursing Elites

1. Which molecules contain only carbon, hydrogen, and oxygen?

• A. Lipids and proteins
• B. Carbohydrates and lipids
• C. Proteins and carbohydrates
• D. Nucleic acids and proteins

Correct answer: B

Rationale: Carbohydrates and lipids are the molecules that contain only carbon, hydrogen, and oxygen. Carbohydrates such as sugars and starches are made up of carbon, hydrogen, and oxygen in a ratio of 1:2:1, while lipids such as fats and oils are composed of carbon, hydrogen, and oxygen as well. Lipids typically contain more carbon and hydrogen atoms compared to oxygen atoms. Proteins contain nitrogen in addition to carbon, hydrogen, and oxygen, while nucleic acids contain phosphorus in addition to carbon, hydrogen, and oxygen. Therefore, choices A, C, and D are incorrect as they include molecules that contain elements other than carbon, hydrogen, and oxygen.

2. How does an enzyme work on a chemical reaction that occurs in a substrate?

• A. An enzyme slows down the chemical reaction.
• B. An enzyme speeds up the chemical reaction.
• C. An enzyme has no effect on the chemical reaction.
• D. An enzyme stops most chemical reactions.

Correct answer: B

Rationale: Enzymes are biological catalysts that facilitate chemical reactions by lowering the activation energy required for the reaction to occur. This allows the reaction to proceed more quickly and efficiently. Enzymes do not change the overall outcome of the reaction, but they significantly increase the rate at which it takes place. Therefore, choice B, 'An enzyme speeds up the chemical reaction,' is the correct answer. Choices A, C, and D are incorrect because enzymes do not slow down, have no effect, or stop chemical reactions; instead, they accelerate the process by lowering the activation energy.

3. Which of the following pH values is most likely for lemon juice?

• A. 3
• B. 5
• C. 7
• D. 9

Correct answer: A

Rationale: Lemon juice is highly acidic with a pH around 2-3, making it more acidic than neutral substances. A pH of 5 is too high for lemon juice, indicating less acidity. Similarly, pH 7 is neutral, and pH 9 would be alkaline, which is not characteristic of lemon juice. Therefore, the correct answer is option A (pH 3).

4. Which part of the brain is responsible for regulating involuntary functions such as breathing and heart rate?

• A. Cerebrum
• B. Cerebellum
• C. Medulla oblongata
• D. Frontal lobe

Correct answer: C

Rationale: The medulla oblongata, located in the brain stem, is responsible for regulating involuntary functions such as breathing and heart rate. It contains vital centers that control these essential functions to maintain life. The cerebrum is primarily involved in higher brain functions like thinking and voluntary movements; the cerebellum plays a crucial role in coordinating movement and balance; and the frontal lobe is responsible for functions such as decision-making, problem-solving, and voluntary muscle movements. Therefore, the correct answer is the medulla oblongata (Choice C).

5. Select the phrase that makes the following sentence grammatically correct: 'Working ____ the mission of the entire committee.'

• A. to peace is
• B. toward peace was
• C. to peace was
• D. toward peace am

Correct answer: B

Rationale: The correct phrase to complete the sentence is 'toward peace was.' In this context, 'toward peace' is the appropriate prepositional phrase to indicate the direction or goal of the work being done. Additionally, the verb tense should be in the past tense ('was') to match the structure of the sentence. Choice A and C are incorrect because 'to peace' does not convey the intended sense of direction or goal. Choice D is incorrect as 'am' is present tense, which does not agree with the past tense structure of the sentence.

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