Metabolism

Q1: What is metabolism?
A: The total of all chemical reactions occurring within a cell to maintain life.

Q2: What is catabolism?
A: The metabolic pathway that breaks down molecules into smaller units and releases energy.

Q3: What is anabolism?
A: The metabolic pathway that builds complex molecules from simpler ones, consuming energy.

Q4: What is the relationship between catabolism and anabolism?
A: Catabolism releases energy that can be used to power anabolic reactions.

Q5: What is energy?
A: The capacity to do work or cause change.

Q6: What is kinetic energy?
A: The energy of motion, such as moving molecules.

Q7: What is potential energy?
A: Stored energy due to an object's position or structure.

Q8: What is chemical energy?
A: Potential energy stored in chemical bonds of molecules.

Q9: What is the first law of thermodynamics?
A: Energy cannot be created or destroyed, only transformed.

Q10: What is the second law of thermodynamics?
A: Every energy transfer increases the entropy (disorder) of the universe.

Q11: What is free energy (Gibbs free energy)?
A: The energy available to do work in a system at constant temperature and pressure.

Q12: What is an exergonic reaction?
A: A reaction that releases free energy and occurs spontaneously.

Q13: What is an endergonic reaction?
A: A reaction that requires an input of energy and is not spontaneous.

Q14: What is ATP and what is its role in metabolism?
A: Adenosine triphosphate; it stores and transfers energy for cellular processes.

Q15: How does ATP release energy?
A: By breaking the bond between its second and third phosphate groups (hydrolysis).

Q16: What is phosphorylation?
A: The addition of a phosphate group to a molecule, often to activate it.

Q17: What is the role of enzymes in metabolism?
A: They speed up metabolic reactions by lowering the activation energy.

Q18: What is activation energy?
A: The minimum energy required for a chemical reaction to occur.

Q19: What environmental factors affect enzyme activity?
A: Temperature, pH, and the presence of inhibitors or activators.

Q20: Why is metabolism tightly regulated?
A: To ensure cells have enough energy, maintain balance, and respond to changes in the environment.