glycogen is what kind of starch

HESI A2

HESI A2 Chemistry Practice Test

1. What type of starch is glycogen?

A. Plant starch
B. Animal starch
C. Glucose
D. Cellulose

Correct answer: B

Rationale: Glycogen is classified as animal starch, not plant starch. It is the storage form of glucose in animals, primarily found in the liver and muscles. Choice A (Plant starch) is incorrect because glycogen is not derived from plants. Choice C (Glucose) is incorrect as glucose is a monosaccharide and not a type of starch. Choice D (Cellulose) is incorrect as cellulose is a structural polysaccharide found in plant cell walls, not the same as glycogen.

2. Why does the diffusion rate increase as a substance is heated?

A. The kinetic energy of particles increases.
B. The space between particles increases.
C. The density of particles decreases.
D. The size of particles increases.

Correct answer: A

Rationale: The correct answer is A. When a substance is heated, the kinetic energy of particles increases, causing them to move faster. This increased movement allows the particles to spread out more rapidly, leading to a higher diffusion rate. Choice B is incorrect because heating does not directly affect the space between particles. Choice C is incorrect because heating does not necessarily lead to a decrease in the density of particles. Choice D is incorrect because the size of particles does not necessarily increase when a substance is heated. Therefore, the correct explanation for the increase in diffusion rate is the rise in kinetic energy of particles.

3. If fifty-six kilograms of a radioactive substance has a half-life of 12 days, how many days will it take the substance to decay naturally to only 7 kilograms?

A. 8
B. 12
C. 36
D. 48

Correct answer: C

Rationale: To decay from 56 kg to 7 kg, the substance needs to go through 3 half-lives (56 kg ÷ 2 ÷ 2 ÷ 2 = 7 kg). Since each half-life is 12 days, the total time required is 12 days per half-life x 3 half-lives = 36 days. Choice A is incorrect because it does not consider the concept of half-lives. Choice B is incorrect because it represents the duration of a single half-life, not the total time required for the decay. Choice D is incorrect as it does not account for the multiple half-lives needed for the substance to decay from 56 kg to 7 kg.

4. Which gas is released during photosynthesis?

A. Carbon dioxide
B. Oxygen
C. Nitrogen
D. Helium

Correct answer: B

Rationale: During photosynthesis, plants utilize carbon dioxide and water to produce glucose and oxygen. Oxygen is released as a byproduct of this process, which is essential for the survival of most living organisms that depend on it for respiration. Therefore, the correct answer is oxygen. Choices A, C, and D are incorrect. Carbon dioxide is utilized in photosynthesis, nitrogen is not directly involved in the process, and helium is not a gas released during photosynthesis.

5. Which substance has a pH value greater than 7?

A. Water
B. Vinegar
C. Lemon juice
D. Baking soda

Correct answer: D

Rationale: The correct answer is D, Baking soda. Baking soda has a pH greater than 7, making it basic. pH values above 7 indicate alkalinity, and baking soda, being a base, has a pH higher than 7. Water, vinegar, and lemon juice have pH values below 7, indicating acidity. Water is neutral with a pH of 7, while vinegar and lemon juice are acidic with pH values lower than 7.