Problem 1 - Campbell Biology

Question

Choose the pair of terms that correctly completes this sentence: Catabolism is to anabolism as __________is to___________ (A) exergonic; spontaneous (B) exergonic; endergonic (C) free energy; entropy (D) work; energy

Step-by-Step Solution

Answer

The correct answer is (B) exergonic; endergonic.

Step 1: Understand the relationship

First, identify the relationship between catabolism and anabolism. Catabolism involves breaking down molecules and releasing energy, whereas anabolism involves building up molecules and consuming energy.

Step 2: Interpret the options

Examine the pairs given in the options: (A) exergonic; spontaneous (B) exergonic; endergonic (C) free energy; entropy (D) work; energy.

Step 3: Select the correct concept

Identify which pair of terms reflects the same relationship. Exergonic reactions release energy (similar to catabolism) and endergonic reactions require energy (similar to anabolism).

Step 4: Verify the answer

Confirm that option (B) exergonic; endergonic properly represents the catabolic and anabolic processes.

Key Concepts

catabolism

Catabolism is a metabolic pathway that breaks down molecules into smaller units. This process is essential for providing the energy needed for various cellular activities. When complex molecules like carbohydrates, fats, and proteins are broken down, they release energy stored in their chemical bonds. This released energy is often harnessed in the form of ATP (adenosine triphosphate).
Key points to remember about catabolism:

• It involves degradation of complex molecules.
• It releases energy, usually in the form of ATP.
• It is essential for sustaining cellular activities and providing energy for anabolic processes.

anabolism

Anabolism is the opposite of catabolism. It is a constructive metabolic process where smaller units like amino acids and monosaccharides are built up into larger, complex molecules such as proteins and polysaccharides. Anabolic processes require energy, which is often supplied by ATP generated during catabolic reactions.
This energy-consuming aspect is crucial for growth, repair, and maintenance of cells.
Key points to remember about anabolism:

• It involves the synthesis of complex molecules from simpler ones.
• It requires energy input, commonly from ATP.
• It is vital for cell growth, repair, and maintenance.

exergonic reactions

Exergonic reactions are chemical reactions that release energy. These reactions are spontaneous, meaning they can proceed without any input of energy. During exergonic reactions, the products have less free energy than the reactants, which means that energy is released into the environment.
This release of energy is similar to what happens during catabolic processes.
Key points about exergonic reactions:

• They release energy to the surroundings.
• They are spontaneous and can occur without additional energy.
• The energy released can be used to power other cellular processes.

endergonic reactions

Endergonic reactions are the opposite of exergonic reactions. These are chemical reactions that absorb energy from their surroundings. Endergonic reactions are not spontaneous; they require an input of energy to proceed.
During these reactions, the products have more free energy than the reactants. This energy requirement makes endergonic reactions similar to anabolic processes, which need energy to synthesize complex molecules.
Key points about endergonic reactions:

• They absorb energy from the environment.
• They are not spontaneous and require energy input.
• The absorbed energy is used for synthesizing molecules and other cellular activities.