enzymes are molecules that serve as for certain biological reactions

ATI TEAS 7

ATI TEAS Science Test

1. Enzymes are __ molecules that serve as _ for certain biological reactions.

A. Enzymes are irrelevant molecules that serve as suppressors for certain biological reactions.
B. Enzymes are acidic molecules that serve as catalysts for certain biological reactions.
C. Enzymes are lipid molecules that serve as catalysts for certain biological reactions.
D. Enzymes are protein molecules that serve as catalysts for certain biological reactions.

Correct answer: D

Rationale: Enzymes are protein molecules that serve as catalysts for certain biological reactions. Enzymes are biological molecules that speed up chemical reactions in living organisms by lowering the activation energy required for the reactions to occur. They are typically proteins that have specific shapes and active sites that allow them to interact with specific substrates and facilitate reactions without being consumed themselves. The other choices are incorrect because enzymes are not irrelevant, acidic, or lipid molecules; they are primarily proteins known for their catalytic properties.

2. 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: The correct answer is C: Can act as both acids and bases. Amphiprotic substances have the ability to donate a proton (act as an acid) or accept a proton (act as a base) depending on the reaction conditions. This dual nature allows them to participate in a wide range of chemical reactions, making them versatile and important in various chemical processes. Choices A and B are incorrect because amphiprotic substances are not limited to reacting with only acids or bases; they can interact with both. Choice D is incorrect because amphiprotic substances are not inert; they actively participate in chemical reactions by donating or accepting protons.

3. What is the most basic unit of structure in living things?

A. Cell
B. Organelle
C. Oxygen
D. Pigment

Correct answer: A

Rationale: The cell is indeed the most basic unit of life, forming the foundation of all living organisms. Cells are the building blocks of all living things, containing organelles that perform specific functions. While oxygen is essential for life, it is not a structural unit. Similarly, pigment is a component found within cells but is not the fundamental unit of structure. Therefore, the correct answer is 'A: Cell.'

4. What presents the correct order of cellular respiration?

A. Glycolysis, Acetyl-CoA, Citric Acid Cycle, Electron Transport Chain
B. Citric Acid Cycle, Glycolysis, Acetyl-CoA, Electron Transport Chain
C. Glycolysis, Acetyl-CoA, Electron Transport Chain, Citric Acid Cycle
D. Glycolysis, Citric Acid Cycle, Electron Transport Chain, Acetyl-CoA

Correct answer: A

Rationale: The correct order of cellular respiration is Glycolysis, Acetyl-CoA, Citric Acid Cycle, and Electron Transport Chain. Glycolysis initiates the breakdown of glucose in the cytoplasm, leading to the formation of pyruvate. This pyruvate is then converted to Acetyl-CoA in the mitochondria, which enters the Citric Acid Cycle to generate energy-rich molecules like NADH and FADH2. Finally, the Electron Transport Chain, located in the inner mitochondrial membrane, utilizes these energy carriers to produce ATP through oxidative phosphorylation. Choice B is incorrect because it starts with the Citric Acid Cycle, which comes after Glycolysis. Choice C is incorrect as it places the Citric Acid Cycle before the Electron Transport Chain. Choice D is incorrect by placing Acetyl-CoA last instead of before the Citric Acid Cycle.

5. Which of the following terms means toward the front of the body?

A. Superior
B. Anterior
C. Inferior
D. Posterior

Correct answer: B

Rationale: The correct answer is B: Anterior. The term 'anterior' specifically refers to the front of the body. In anatomical terms, anterior is the opposite of posterior, which means toward the back of the body. Superior and inferior, choices A and C, respectively, refer to top and bottom directions, not front and back. Therefore, 'Anterior' is the most appropriate term for describing a position toward the front of the body.