Metabolism and Photosynthesis Quiz

Front

Metabolism

Back

Sum of all chemical reactions in a cell

Answer explanation

Metabolism refers to the sum of all chemical reactions in a cell, including both the breakdown of substances and the synthesis of new compounds. This encompasses processes like energy production and nutrient utilization.

Front

Breakdown of large molecules

Back

Catabolism

Answer explanation

Catabolism is the metabolic process that breaks down large molecules into smaller ones, releasing energy. In contrast, anabolism builds larger molecules from smaller ones. Therefore, the correct answer is catabolism.

Front

Example of potential energy

Back

ATP

Answer explanation

ATP is a molecule that stores potential energy in its high-energy phosphate bonds, making it an example of potential energy. In contrast, a moving car, flowing water, and a walking person represent kinetic energy.

Front

Second Law of Thermodynamics

Back

Energy transfer not 100% efficient; some energy lost as heat.

Answer explanation

The Second Law of Thermodynamics states that energy transfers are never 100% efficient, as some energy is always lost as heat. This principle highlights the inherent limitations in energy conversion processes.

Front

Energy currency in cells

Back

ATP

Answer explanation

ATP (adenosine triphosphate) is the primary energy currency in cells, providing energy for various cellular processes. While NADH and FADH2 are involved in energy transfer, ATP is the direct source of energy for cellular activities.

Front

Process of adding phosphate to ADP

Back

Phosphorylation

Answer explanation

The process of adding a phosphate group to ADP to form ATP is called phosphorylation. This reaction is essential for energy storage in cells, while hydrolysis refers to breaking down ATP, and oxidation and fermentation are different metabolic processes.

Front

Type of reaction that releases energy

Back

Exergonic

Answer explanation

Exergonic reactions release energy as they proceed, making them spontaneous. In contrast, endergonic reactions require energy input, while anabolic reactions build molecules and redox reactions involve electron transfer.

Front

Enzyme that lowers activation energy

Back

All enzymes

Answer explanation

All enzymes lower the activation energy of reactions in cells, facilitating biochemical processes. While specific enzymes like catalase and hexokinase have unique functions, the statement applies to all enzymes collectively.

Front

Factors affecting enzymatic activity

Back

pH, temperature, substrate concentration

Answer explanation

Enzymatic activity is influenced by pH, temperature, and substrate concentration. These factors affect the enzyme's ability to bind to substrates and catalyze reactions, making this choice the most comprehensive.

Front

Competitive inhibition: Inhibitor binds to?

Back

Active site

Answer explanation

In competitive inhibition, the inhibitor competes with the substrate for the active site of the enzyme. By binding to the active site, it prevents the substrate from attaching, thus inhibiting the enzyme's activity.