what is the main function of peroxisomes in the cell

ATI TEAS 7

Mometrix TEAS 7 science practice test

1. What is the main function of peroxisomes in the cell?

A. To break down hydrogen peroxide
B. To synthesize lipids and other cellular components
C. To package and transport proteins
D. To store genetic material

Correct answer: A

Rationale: Peroxisomes are membrane-bound organelles found in eukaryotic cells that contain enzymes involved in various metabolic processes. One of the main functions of peroxisomes is to break down hydrogen peroxide, a toxic byproduct of metabolism, into water and oxygen through the action of the enzyme catalase. This process helps protect the cell from oxidative damage caused by hydrogen peroxide. While peroxisomes are involved in other metabolic functions such as lipid metabolism and the synthesis of bile acids, their primary role is the breakdown of hydrogen peroxide. Choices B, C, and D are incorrect because peroxisomes are not primarily responsible for synthesizing lipids, packaging and transporting proteins, or storing genetic material within the cell.

2. Which of the following best describes the term homeostasis?

A. The ability to maintain a constant body temperature
B. The ability to maintain a stable internal environment
C. The ability to increase body temperature when cold
D. The ability to regulate blood glucose levels

Correct answer: B

Rationale: The correct answer is B, 'The ability to maintain a stable internal environment.' Homeostasis refers to the body's ability to regulate and maintain a stable internal environment, which includes variables like body temperature, pH levels, and fluid balance. It involves processes that help keep the body's internal conditions within a narrow range, despite external changes. While maintaining body temperature is a component of homeostasis, it is not the complete definition of the term. Choice C, 'The ability to increase body temperature when cold,' is incorrect as homeostasis aims to maintain stability rather than promoting temperature increases in response to external conditions. Choice D, 'The ability to regulate blood glucose levels,' is also incorrect as this is a specific function related to glucose homeostasis, which is a part of overall homeostatic processes but not the sole definition of homeostasis itself.

3. Where does cellular respiration, the process of converting chemical energy into ATP, take place in eukaryotic cells?

A. Nucleus
B. Ribosomes
C. Mitochondria
D. Golgi apparatus

Correct answer: C

Rationale: Cellular respiration, the process of converting chemical energy into ATP, takes place in the mitochondria of eukaryotic cells. The mitochondria are known as the powerhouse of the cell because they are responsible for generating most of the cell's ATP through the process of cellular respiration. This process involves the breakdown of glucose and other organic molecules to produce ATP, which is the primary energy currency of the cell. The other organelles listed in the options (nucleus, ribosomes, and Golgi apparatus) do not play a direct role in cellular respiration. The nucleus is responsible for storing genetic material, ribosomes are involved in protein synthesis, and the Golgi apparatus is involved in processing and packaging proteins for secretion or internal use.

4. Which term refers to the act of inhaling foreign objects into the airway?

A. Expiration
B. Respiration
C. Aspiration
D. Inhalation

Correct answer: C

Rationale: Among the options provided, aspiration is the term that specifically refers to the act of inhaling foreign objects into the airway. Expiration refers to breathing out, respiration is the overall process of gas exchange in the body, and inhalation is the act of breathing in air or other substances into the lungs. Therefore, the correct answer is C, aspiration. It is crucial to understand these terms in the context of airway management and respiratory care to ensure proper identification and treatment of related conditions.

5. What term refers to the mechanical act of breathing?

A. Diffusion
B. Perfusion
C. Respiration
D. Ventilation

Correct answer: D

Rationale: Ventilation is the correct answer as it specifically refers to the mechanical process of breathing air in and out of the lungs. Diffusion (choice A) is the movement of molecules from an area of high concentration to low concentration, not related to the mechanical act of breathing. Perfusion (choice B) is the process of blood flow through the tissues and organs, not directly related to breathing mechanically. Respiration (choice C) involves the exchange of oxygen and carbon dioxide at the cellular level, different from the mechanical act of breathing.