Nursing Elites

1. Why is yeast used to make bread rise?

• A. It engages in photosynthesis, which produces oxygen gas.
• B. Carbon dioxide forms while yeast carries out photosynthesis.
• C. Yeast carries out fermentation, producing ethanol and carbon dioxide.
• D. Yeast breathes in oxygen and produces carbon dioxide through aerobic respiration.

Correct answer: C

Rationale: Yeast is used to make bread rise because it carries out fermentation, producing carbon dioxide gas. The carbon dioxide gas gets trapped in the dough, causing it to rise and create a fluffy texture in the bread. Choices A, B, and D are incorrect because yeast does not engage in photosynthesis, so it does not produce oxygen gas, does not carry out photosynthesis to form carbon dioxide, and does not produce carbon dioxide through aerobic respiration. Yeast's fermentation process is essential for bread rising.

2. Which of the following are considered the most important molecules in biology?

• A. Carbohydrates, lipids, protein, and nucleic acids
• B. Carbohydrates, lipids, protein, and calcium
• C. Carbohydrates, lipids, protein, and sulfur
• D. Carbohydrates, lipids, protein, and iron

Correct answer: A

Rationale: The correct answer is A: Carbohydrates, lipids, protein, and nucleic acids are considered the most important molecules in biology. Carbohydrates are essential for providing energy, lipids for storing energy and forming cell membranes, proteins for various structural and functional roles, and nucleic acids (DNA and RNA) for storing genetic information. Choices B, C, and D are incorrect because while carbohydrates, lipids, and proteins are crucial biomolecules, calcium, sulfur, and iron are not considered among the most important molecules in biology.

3. Which organelle provides storage space for the cell?

• A. Mitochondrion
• B. Vacuole
• C. Cell membrane
• D. Ribosome

Correct answer: B

Rationale: The correct answer is B: Vacuole. The vacuole is the organelle responsible for providing storage space in the cell. It stores water, nutrients, waste products, and other essential materials required by the cell. Vacuoles are crucial for maintaining cell structure and regulating cellular processes. Mitochondrion (choice A) is known as the powerhouse of the cell, responsible for producing energy. The cell membrane (choice C) is a protective barrier around the cell, regulating what enters and exits the cell. Ribosomes (choice D) are involved in protein synthesis, not storage.

4. Physical factors such as temperature and pH can alter enzyme activity because they have an effect on the enzyme's ___________.

• A. acidity
• B. shape
• C. chemistry
• D. substrate

Correct answer: B

Rationale: Physical factors such as temperature and pH can alter enzyme activity by affecting the enzyme's shape. Enzymes rely on their specific shapes to function properly and catalyze reactions. Any changes in temperature or pH can disrupt these shapes, causing the enzyme to become denatured and lose its functionality. Therefore, alterations in temperature and pH can impact enzyme activity by directly affecting their shapes. Choices A, C, and D are incorrect because while pH can affect acidity and chemical properties of the enzyme, and temperature can influence the enzyme-substrate interaction, the primary reason for enzyme activity alteration due to temperature and pH is the change in the enzyme's shape.

5. Which cell organelle functions to transport materials from the endoplasmic reticulum throughout the cell?

• A. Ribosome
• B. Golgi apparatus
• C. Lysosome
• D. Vacuole

Correct answer: B

Rationale: The Golgi apparatus is the correct answer because it functions to transport materials from the endoplasmic reticulum throughout the cell. Ribosomes are responsible for protein synthesis, not transportation of materials. Lysosomes contain enzymes for digestion and waste removal, not for transporting materials. Vacuoles are primarily involved in storage, waste disposal, and maintaining turgor pressure, not in transporting materials from the endoplasmic reticulum.

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