The process in which complex substances are broken down into simpler ones is referred to as
anabolism
catabolism
metabolism
tropism
Correct Answer:B
Explanation
The correct option is B. catabolism.
Detailed Explanation:
Understanding the Terms:
Anabolism: This is the process of building up complex molecules from simpler ones. It involves the synthesis of larger molecules, such as proteins from amino acids, and requires energy input.
Catabolism: This is the process of breaking down complex substances into simpler ones. It involves the degradation of larger molecules, such as carbohydrates into glucose, and releases energy.
Metabolism: This is a broad term that encompasses all chemical reactions in the body, including both anabolism and catabolism. It is the sum of all metabolic processes.
Tropism: This refers to the growth or movement of an organism in response to an environmental stimulus, such as light (phototropism) or gravity (gravitropism). It is not related to the breakdown of substances.
Why Catabolism is Correct:
Catabolism is specifically defined as the metabolic pathway that breaks down molecules into smaller units, releasing energy in the process. This energy is often stored in the form of ATP (adenosine triphosphate), which can then be used for various cellular activities.
For example, during cellular respiration, glucose (a complex carbohydrate) is broken down into carbon dioxide and water, releasing energy that the cell can use.
Why the Other Options are Incorrect:
A. Anabolism: This option is incorrect because anabolism refers to the building up of complex molecules, not the breakdown. It is the opposite of catabolism.
C. Metabolism: While metabolism includes catabolism, it is a broader term that encompasses both catabolic and anabolic processes. Therefore, it does not specifically answer the question about breaking down substances.
D. Tropism: This option is unrelated to the biochemical processes of breaking down substances. Tropism deals with growth responses to environmental stimuli, making it irrelevant to the question.
Summary of Key Points:
Catabolism is the process of breaking down complex substances into simpler ones, releasing energy.
Anabolism is the opposite process, involving the synthesis of complex molecules from simpler ones.
Metabolism includes both catabolic and anabolic processes, making it a broader term.
Tropism is unrelated to metabolic processes and focuses on growth responses to stimuli.
Revision Summary:
Catabolism = breakdown of complex substances (correct answer: B).
Anabolism = synthesis of complex substances (not the answer).
Metabolism = all chemical reactions in the body (too broad).
Tropism = growth response to stimuli (not related to the question).