Nursing Elites

1. What kind of bond links amino acids together?

• A. Hydrogen bond
• B. Ionic bond
• C. Disulfide bond
• D. Covalent bond

Correct answer: D

Rationale: Rationale: Amino acids are linked together by covalent bonds to form proteins. A covalent bond is a strong chemical bond formed by the sharing of electrons between atoms. In the case of amino acids, the covalent bond that links them together is called a peptide bond. This bond forms between the amino group of one amino acid and the carboxyl group of another amino acid, resulting in the formation of a peptide chain. Hydrogen bonds, ionic bonds, and disulfide bonds can also play roles in protein structure and stability, but the primary bond linking amino acids together in a protein chain is the covalent peptide bond.

2. Which of the following is a common property of bases?

• A. Conductivity in aqueous solutions
• B. Sour taste
• C. Reactivity with metals to produce hydrogen gas
• D. Turns red litmus paper blue

Correct answer: D

Rationale: Bases are substances that can accept protons or donate hydroxide ions in a chemical reaction. One common property of bases is that they turn red litmus paper blue. This is a classic test to distinguish between acids (which turn blue litmus paper red) and bases. Conductivity in aqueous solutions (Option A) is a property of both acids and bases, sour taste (Option B) is a property of acids, and reactivity with metals to produce hydrogen gas (Option C) is a property of acids, not bases.

3. Differentiate between epithelial and connective tissue.

• A. Epithelial tissue is exclusively found in the lungs, while connective tissue supports tendons.
• B. Both are composed of cells, but epithelial tissue lines surfaces and glands, while connective tissue binds other tissues.
• C. Epithelial tissue is more vascularized, while connective tissue is responsible for muscle contraction.
• D. Epithelial tissue is the largest tissue type, while connective tissue is the smallest.

Correct answer: B

Rationale: Epithelial tissue covers surfaces and lines organs, while connective tissue provides support and structure throughout the body. Both are composed of cells, but their functions and locations differ.

4. What is the main function of calcitonin, a hormone produced by the thyroid gland?

• A. Stimulate metabolism and heat production
• B. Increase calcium absorption from the intestines
• C. Enhance bone growth and development
• D. Lower blood calcium levels

Correct answer: D

Rationale: The correct answer is D: 'Lower blood calcium levels.' Calcitonin is a hormone produced by the thyroid gland that helps regulate calcium levels in the blood. It works by inhibiting the breakdown of bone, which in turn lowers the amount of calcium released into the bloodstream. This process helps to decrease blood calcium levels when they are too high. Options A, B, and C are not functions of calcitonin; instead, they are more closely associated with other hormones such as thyroid hormones, vitamin D, and growth hormone, respectively.

5. The word "obscurity" can be replaced with which of the following without changing the meaning?

• A. Prominence
• B. Seclusion
• C. Destruction
• D. Transformation

Correct answer: B

Rationale: Both "obscurity" and "seclusion" imply being hidden or unknown. Prominence, destruction, and transformation do not convey the same meaning.

6. Which of the following is a property of amphiprotic substances?

• A. React with acids only
• B. React with bases only
• C. Can act as both acids and bases
• D. Are inert in chemical reactions

Correct answer: C

Rationale: Amphiprotic substances can donate or accept a proton, so they can act as both acids and bases. The other choices do not accurately describe amphiprotic substances.

Similar Questions