how many amino acids are essential for human life

HESI A2

HESI A2 Chemistry Practice Test

1. How many amino acids are essential for human life?

A. 22
B. 20
C. 18
D. 24

Correct answer: B

Rationale: There are 20 essential amino acids required for human life. These amino acids cannot be synthesized by the body and must be obtained through the diet. They play crucial roles in various physiological functions and are necessary for protein synthesis and overall health. Choice A is incorrect because there are not 22 essential amino acids. Choice C is incorrect as there are more than 18 essential amino acids. Choice D is incorrect as there are not 24 essential amino acids for human life.

2. What is a nit?

A. abscess
B. parasite
C. bandage
D. infection

Correct answer: B

Rationale: A nit is a kind of parasite, specifically the egg of a louse. Nits are typically found attached to hair close to the scalp and are commonly associated with head lice infestations. Choice A, 'abscess,' is incorrect as an abscess is a collection of pus caused by an infection. Choice C, 'bandage,' is incorrect as it is a material used for covering wounds. Choice D, 'infection,' is incorrect as it refers to the invasion and multiplication of microorganisms in body tissues.

3. Which gland controls Calciferol?

A. Thyroid
B. Pituitary
C. Parathyroid
D. Hypothalamus

Correct answer: C

Rationale: Calciferol, commonly known as Vitamin D, is regulated by the parathyroid gland, not the thyroid, pituitary, or hypothalamus. The parathyroid gland plays a crucial role in maintaining calcium and phosphorus balance in the body by regulating the production of calcitriol, the active form of Vitamin D. This hormone helps in the absorption of calcium from the intestines and its reabsorption in the kidneys to maintain proper calcium levels in the blood. Therefore, the correct answer is the Parathyroid gland (Choice C). Choices A, B, and D are incorrect as they do not have a direct role in controlling Calciferol.

4. Which word is used incorrectly? 'I did the work before he asked me to.'

A. did
B. work
C. asked
D. before

Correct answer: A

Rationale: The word 'did' is correctly used in the sentence to form the past tense of the verb 'do.' In this context, 'did' is the appropriate term. The other words in the sentence, 'work,' 'asked,' and 'before,' are all used correctly and do not represent an incorrect word choice. Therefore, 'did' is the only word that is not used incorrectly in the given sentence.

5. Express 2/5 as a decimal.

A. 0.2
B. 0.25
C. 0.4
D. 2.5

Correct answer: C

Rationale: To express 2/5 as a decimal, you divide the numerator (2) by the denominator (5). 2 ÷ 5 = 0.4. Choice A (0.2) is the decimal equivalent of 1/5, not 2/5. Choice B (0.25) is the decimal equivalent of 1/4, not 2/5. Choice D (2.5) is not the correct decimal equivalent of 2/5 as it is greater than 1.